---
title: How animals sleep: half-asleep dolphins, standing horses, short-slee… — how Mova does on the tests · Biology
description: Lesson 390 of the biology course of Mova's primary school: 5 of 11 tests right, exam 2 of 4, every question with the options, the student's choice, the right answer and why it chose.
---

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# How animals sleep: half-asleep dolphins, standing horses, short-sleeping giraffes and birds that nap in the air

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**Tests:** 5 of 11 right · **Exam:** 2 of 4 right · **Kind:** plain · **Understood:** 11 of 15 · **Run:** 2026-10-18, commit `f3c23ea72`

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Lesson 390 of the biology course of Mova's primary school, as Mova's small model took its tests: it had read this lesson and the ones before it and learned from their exercises. Each test shows the options in the order the student saw them, its choice, the right answer, the score of every option and why it chose. The lesson itself, sentence by sentence with trees and pragmatics: [the lesson in the corpora](https://md.mova.elamur.ai/free/en/corpora/school/biology/390-how-animals-sleep-half-asleep-dolphins-standing-horses-short-sleeping-giraffes-and-birds-that-nap-in-the-air/).

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Every question of this lesson and each of its options parsed by Mova, with trees and pragmatics: [the lesson's questions in the corpora](https://md.mova.elamur.ai/free/en/corpora/questions/biology/390-how-animals-sleep-half-asleep-dolphins-standing-horses-short-sleeping-giraffes-and-birds-that-nap-in-the-air/).

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### Test 1 · right ✓ {#t1}

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In Ice Age, Sid the sloth is lazy and sleepy. A friend says sloths sleep twenty hours a day. What is right?

- **1.** Yes, twenty hours in the wild, even more than in the zoo — no support
- **2.** Sloths never sleep — score -2
- **3.** Wild sloths were reported to sleep about nine or ten hours — **← Mova's choice** · **✓ the right answer** · score 2
- **4.** Sloths sleep only one hour — score 2

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**Why:** It took the question to ask which statement is true. It chose option 3 with score 2, tied with another option at 2 (the first shown, or the one claiming less beyond what it knows, wins). Its support: lesson 390, line 11: «Scientists reported that wild sloths sleep about nine or ten hours a day, not twenty; the big number came from sloths in zoos.», reached through the option's own match among the sentences about the question's things. What matched: the same action «sleep» (+1); the same property (+1). · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/biology/390-how-animals-sleep-half-asleep-dolphins-standing-horses-short-sleeping-giraffes-and-birds-that-nap-in-the-air/t1/)

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### Test 2 · wrong ✗ {#t2}

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Count them: a row of 6 ducks sleeps on a log, and the 2 at the ends each keep 1 eye open. How many eyes are open?

- **1.** Twelve — **← Mova's choice** · score 1
- **2.** Two — **✓ the right answer** · score 1
- **3.** Four — score 1
- **4.** Six — score 1

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**Why:** It took the question to ask what it is done to. It chose option 1 with score 1, tied with another option at 1 (the first shown, or the one claiming less beyond what it knows, wins). Its support: lesson 152, line 18: «Fish rest and sleep, but most have no eyelids, so their eyes stay open.», reached through the remembered sentence the question matched. What matched: the same property (+1). The right option, 2, scored 1. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/biology/390-how-animals-sleep-half-asleep-dolphins-standing-horses-short-sleeping-giraffes-and-birds-that-nap-in-the-air/t2/)

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### Test 3 · wrong ✗ {#t3}

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Count them: 3 horses doze, each resting one back hoof lifted off the ground. How many hooves are on the ground?

- **1.** Six — **← Mova's choice** · no support
- **2.** Twelve — no support
- **3.** Nine — **✓ the right answer** · no support
- **4.** Three — no support

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**Why:** No option found support in what it remembers, so it guessed: it took the first option shown. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/biology/390-how-animals-sleep-half-asleep-dolphins-standing-horses-short-sleeping-giraffes-and-birds-that-nap-in-the-air/t3/)

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### Test 4 · right ✓ {#t4}

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In Tom and Jerry, Tom sleeps flat on his back snoring for hours. Which real animal often dozes standing up instead?

- **1.** The horse — **← Mova's choice** · **✓ the right answer** · score 6
- **2.** The koala — no support
- **3.** The bat — no support
- **4.** The house cat — score 5

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**Why:** It took the question to ask who or what does it. It chose option 1 with score 6, against 5 for the next best. Its support: lesson 390, line 2: «Every animal sleeps in a way that fits its life. Ducks at the ends of a row keep the outward eye open, frigatebirds nap for seconds while gliding over the ocea…», reached through the same lesson line as the sentence the question matched. What matched: the same action «doze» (+3); it fills the role the question asks for (+2); the same doer «horses» (+1). · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/biology/390-how-animals-sleep-half-asleep-dolphins-standing-horses-short-sleeping-giraffes-and-birds-that-nap-in-the-air/t4/)

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### Test 5 · right ✓ {#t5}

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«my goldfish is dead, it's just hanging there with its eyes open» What is probably happening?

- **1.** It is staring at you because it wants food — score 1
- **2.** It is holding its breath — score 1
- **3.** It is definitely dead — score 1
- **4.** It is resting; fish have no eyelids — **← Mova's choice** · **✓ the right answer** · score 5

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**Why:** It took the question to ask what happens next. It chose option 4 with score 5, against 1 for the next best. Its support: lesson 390, line 14: «Fish rest by slowing down and hovering still; they have no eyelids, so their eyes stay open, and some parrotfish sleep in a bubble of slime.», reached through a sentence linked to the one the question matched. What matched: the same doer «fish» (+2); the same thing acted on «eyelids» (+2); the same light verb (be, have, do, get, go) (+1). · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/biology/390-how-animals-sleep-half-asleep-dolphins-standing-horses-short-sleeping-giraffes-and-birds-that-nap-in-the-air/t5/)

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### Test 6 · wrong ✗ {#t6}

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What would happen if a giraffe lay down for a long sleep with lions nearby?

- **1.** Lions never hunt giraffes — no support
- **2.** It would jump up in a second — no support
- **3.** Nothing, giraffes sleep lying all night — **← Mova's choice** · score 7
- **4.** It would be slow to get up and in danger — **✓ the right answer** · score 4

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**Why:** It took the question to ask what happens next. It chose option 3 with score 7, against 4 for the next best. Its support: lesson 390, line 9: «Horses can lock their legs and doze standing, but for their deepest sleep they must lie down for a short time.», reached through what followed the sentence the question matched. What matched: the same action «sleep» (+6); a different doer (counts against) (+1). The right option, 4, scored 4. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/biology/390-how-animals-sleep-half-asleep-dolphins-standing-horses-short-sleeping-giraffes-and-birds-that-nap-in-the-air/t6/)

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### Test 7 · right ✓ {#t7}

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«penguin naps of 4 seconds? that's not proper sleep lol» What is right?

- **1.** Over ten thousand of them added up to about eleven hours — **← Mova's choice** · **✓ the right answer** · no support
- **2.** They do not count as sleep at all — no support
- **3.** Penguins nap for four hours each time, not four seconds as people say — no support
- **4.** Penguins sleep only in winter — no support

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**Why:** Nothing it remembers matched the question, so it guessed: it took the first option shown. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/biology/390-how-animals-sleep-half-asleep-dolphins-standing-horses-short-sleeping-giraffes-and-birds-that-nap-in-the-air/t7/)

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### Test 8 · wrong ✗ {#t8}

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«elephants sleep loads, they're huge» What is right?

- **1.** They sleep all winter in caves, like bears, because they are so big — score 3
- **2.** They sleep only in water — **← Mova's choice** · score 4
- **3.** They sleep twenty hours — score 1
- **4.** Wild elephants were reported to sleep only about two hours a night — **✓ the right answer** · score 3

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**Why:** It took the question to ask which statement is true. It chose option 2 with score 4, against 3 for the next best. Its support: lesson 21, line 11: «Elephants can swim and use the trunk as a snorkel, keeping only its tip above the water.», reached through the option's own match among the sentences about the question's things. What matched: the same place «water» (+4). The right option, 4, scored 3. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/biology/390-how-animals-sleep-half-asleep-dolphins-standing-horses-short-sleeping-giraffes-and-birds-that-nap-in-the-air/t8/)

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### Test 9 · wrong ✗ {#t9}

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Why would a bird sleep less while flying over the sea?

- **1.** It sleeps more at sea — **← Mova's choice** · no support
- **2.** It must keep steering and watching, with nowhere safe to land — **✓ the right answer** · no support
- **3.** It is never tired at sea — no support
- **4.** Seawater keeps it awake — no support

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**Why:** No option found support in what it remembers, so it guessed: it took the first option shown. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/biology/390-how-animals-sleep-half-asleep-dolphins-standing-horses-short-sleeping-giraffes-and-birds-that-nap-in-the-air/t9/)

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### Test 10 · right ✓ {#t10}

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«koala sleeps all day, lazy git» What is the real reason?

- **1.** Its leaves give little energy, so sleep saves energy — **← Mova's choice** · **✓ the right answer** · score 6
- **2.** Koalas are lazy by choice and could be busy if they wanted to — no support
- **3.** It stays up all night partying — no support
- **4.** It is ill every day — score 1

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**Why:** It took the question to ask which statement is true. It chose option 1 with score 6, against 1 for the next best. Its support: lesson 55, line 10: «Giraffes sleep very little, in short naps, mostly standing, because getting up takes a long time with lions around; koalas sleep about 18 to 22 hours a day, be…», reached through a sentence linked to the one the question matched. What matched: the same action «give» (+3); the same doer «gum leaves» (+2); the same thing acted on «little energy» (+1). · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/biology/390-how-animals-sleep-half-asleep-dolphins-standing-horses-short-sleeping-giraffes-and-birds-that-nap-in-the-air/t10/)

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### Test 11 · wrong ✗ {#t11}

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Why do some bats sleep about twenty hours a day?

- **1.** They are always cold and stay asleep to keep warm — score 3
- **2.** They rest when there are no insects to catch — **✓ the right answer** · score 3
- **3.** They are afraid of the dark — score 4
- **4.** They hang upside down for fun — **← Mova's choice** · score 5

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**Why:** It took the question to ask why something happens (its cause). It chose option 4 with score 5, against 4 for the next best. Its support: lesson 55, line 11: «Bats sleep hanging upside down with their foot tendons locked, and in cold countries they hibernate in caves and attics; bats are not blind.», reached through the same lesson line as the sentence the question matched. What matched: the same action «hang down» (+5); the same thing acted on «upside» (+1). Against it: the same property (-1). The right option, 2, scored 3. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/biology/390-how-animals-sleep-half-asleep-dolphins-standing-horses-short-sleeping-giraffes-and-birds-that-nap-in-the-air/t11/)

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### Exam question 1 · formal language · wrong ✗ {#e1}

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Select the response consistent with the established facts concerning the sleep of dolphins.

- **1.** Dolphins sleep with the entire brain at the bottom of the sea — **← Mova's choice** · score 4
- **2.** Dolphins sleep only upon the shore — score 1
- **3.** One cerebral hemisphere sleeps while the other remains awake, the two alternating — **✓ the right answer** · no support
- **4.** Dolphins abstain from sleep entirely — no support

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**Why:** It took the question to ask which statement is true. It chose option 1 with score 4, against 1 for the next best. Its support: lesson 55, line 9: «Dolphins sleep with half their brain at a time and one eye open, so they can still come up to breathe and watch for danger.», reached through the option's own match among the sentences about the question's things. What matched: the same circumstance (+3); the same action «sleep» (+1). The right option, 3, found no support in what it remembers. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/biology/390-how-animals-sleep-half-asleep-dolphins-standing-horses-short-sleeping-giraffes-and-birds-that-nap-in-the-air/e1/)

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### Exam question 2 · formal language · wrong ✗ {#e2}

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Ascertain the approximate daily duration of sleep reported for wild elephants in Africa.

- **1.** Six hours — **← Mova's choice** · no support
- **2.** Ten hours — no support
- **3.** Two hours — **✓ the right answer** · no support
- **4.** Twenty hours — no support

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**Why:** No option found support in what it remembers, so it guessed: it took the first option shown. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/biology/390-how-animals-sleep-half-asleep-dolphins-standing-horses-short-sleeping-giraffes-and-birds-that-nap-in-the-air/e2/)

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### Exam question 3 · formal language · right ✓ {#e3}

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Identify the principal reason for which the duration of sleep attributed to sloths was formerly overstated.

- **1.** Sloths were observed only in winter — no support
- **2.** Sloths conceal themselves while awake — score 3
- **3.** Observers confused sloths with koalas — no support
- **4.** Early observations were made upon animals kept in zoos — **← Mova's choice** · **✓ the right answer** · score 5

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**Why:** It took the question to ask which statement is true. It chose option 4 with score 5, against 3 for the next best. Its support: lesson 286, line 13: «Mice and rats eat stored grain, which is one reason farmers have kept cats for thousands of years.», reached through the same lesson line as the sentence the question matched. What matched: the same action «keep» (+4); the same thing acted on «cats» (+1). · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/biology/390-how-animals-sleep-half-asleep-dolphins-standing-horses-short-sleeping-giraffes-and-birds-that-nap-in-the-air/e3/)

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### Exam question 4 · formal language · right ✓ {#e4}

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Which of the following statements most accurately characterises the sleep of frigatebirds in flight?

- **1.** They never sleep at any time — no support
- **2.** They sleep less than an hour daily, chiefly in naps of a few seconds — **← Mova's choice** · **✓ the right answer** · score 1
- **3.** They sleep only upon the surface of the sea — no support
- **4.** They sleep twelve hours continuously while gliding in the air — score 1

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**Why:** It took the question to ask who or what does it. It chose option 2 with score 1, tied with another option at 1 (the first shown, or the one claiming less beyond what it knows, wins). Its support: lesson 390, line 12: «Wild elephants in Africa were reported to sleep only about two hours a night, mostly standing, and some nights not at all.», reached through the remembered sentence the question matched. What matched: the same action «sleep» (+1). · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/biology/390-how-animals-sleep-half-asleep-dolphins-standing-horses-short-sleeping-giraffes-and-birds-that-nap-in-the-air/e4/)

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