--- title: Defences: skunks, porcupines, hedgehogs and armour — a lesson of Mova's school · trees and pragmatics description: «Defences: skunks, porcupines, hedgehogs and armour», a lesson of the biology course of Mova's primary school, sentence by sentence with dependency trees and pragmatics. It begins: An animal that cannot run fast can still be very hard to eat: it can be spiky, smelly, or covered in armour like a knig --- [Mova](https://md.mova.elamur.ai/free/en/) · [this page in HTML](https://mova.elamur.ai/free/en/corpora/school/biology/248-defences-skunks-porcupines-hedgehogs-and-armour/) [home](https://md.mova.elamur.ai/free/en/) / [corpora](https://md.mova.elamur.ai/free/en/corpora/) / [school](https://md.mova.elamur.ai/free/en/corpora/school/) / [Biology](https://md.mova.elamur.ai/free/en/corpora/school/biology/) / Defences: skunks, porcupines, hedgehog… # Defences: skunks, porcupines, hedgehogs and armour Lesson 248 of the biology course of Mova's primary school: 14 sentences, each with its syntax tree and pragmatics. The lessons are written for Mova, and their agreed trees are part of Mova corpus 0.4 (CC BY-SA 4.0). How Mova does on its tests: [the lesson at school](https://md.mova.elamur.ai/free/en/school-run/biology/248-defences-skunks-porcupines-hedgehogs-and-armour/). - [0](https://md.mova.elamur.ai/free/en/corpora/school/biology/248-defences-skunks-porcupines-hedgehogs-and-armour/0/) — An animal that cannot run fast can still be very hard to eat: it can be spiky, smelly, or covered in armour like a knight. - [1](https://md.mova.elamur.ai/free/en/corpora/school/biology/248-defences-skunks-porcupines-hedgehogs-and-armour/1/) — A hedgehog rolls into a tight ball of spines, a pangolin curls up in scales so tough that a lion cannot bite through, and a tortoise pulls its head into a shell that is part of its own skeleton. - [3](https://md.mova.elamur.ai/free/en/corpora/school/biology/248-defences-skunks-porcupines-hedgehogs-and-armour/3/) — Some defences sound like cartoons but are real: a beetle that fires boiling chemicals from its bottom with a pop, and a lizard that squirts blood from its eyes. - [4](https://md.mova.elamur.ai/free/en/corpora/school/biology/248-defences-skunks-porcupines-hedgehogs-and-armour/4/) — Cartoons get some of it wrong, though: porcupines cannot shoot their quills, and a tortoise can never climb out of its shell. - [5](https://md.mova.elamur.ai/free/en/corpora/school/biology/248-defences-skunks-porcupines-hedgehogs-and-armour/5/) — Skunks spray a very smelly oily liquid from glands under the tail at an attacker's face, but first warn by stamping, hissing and raising the tail, and spotted skunks even do a handstand; the smell can carry over a kilometre, and tomato juice does not really wash it off. - [7](https://md.mova.elamur.ai/free/en/corpora/school/biology/248-defences-skunks-porcupines-hedgehogs-and-armour/7/) — A hedgehog has about 5,000 to 7,000 spines, which are hollow hairs without barbs, and strong muscles to curl up tight, but badgers are strong enough to unroll one. - [8](https://md.mova.elamur.ai/free/en/corpora/school/biology/248-defences-skunks-porcupines-hedgehogs-and-armour/8/) — Armadillo armour is made of bone plates covered with tough skin; only the three-banded armadillo can roll into a full ball, and the nine-banded armadillo almost always has four identical babies. - [9](https://md.mova.elamur.ai/free/en/corpora/school/biology/248-defences-skunks-porcupines-hedgehogs-and-armour/9/) — Pangolins are mammals covered in scales made of keratin, like your nails, and roll up so tight that a lion cannot bite through; they are among the most trafficked mammals because some people wrongly think the scales are medicine. - [10](https://md.mova.elamur.ai/free/en/corpora/school/biology/248-defences-skunks-porcupines-hedgehogs-and-armour/10/) — A tortoise's shell is part of its skeleton, joined to its backbone and ribs, so it can never climb out; some tortoises live over 150 years, and Jonathan on Saint Helena was reported to be born around 1832. - [11](https://md.mova.elamur.ai/free/en/corpora/school/biology/248-defences-skunks-porcupines-hedgehogs-and-armour/11/) — Sea urchins are covered with movable spines that point towards a threat, and their mouth underneath has five teeth called Aristotle's lantern. - [12](https://md.mova.elamur.ai/free/en/corpora/school/biology/248-defences-skunks-porcupines-hedgehogs-and-armour/12/) — Stink bugs release bad-smelling chemicals when disturbed, and smells work well as defences because predators learn quickly. - [13](https://md.mova.elamur.ai/free/en/corpora/school/biology/248-defences-skunks-porcupines-hedgehogs-and-armour/13/) — The bombardier beetle mixes two chemicals in a chamber in its bottom, they react with a burst of heat, and it fires a boiling hot spray with a pop in almost any direction. - [14](https://md.mova.elamur.ai/free/en/corpora/school/biology/248-defences-skunks-porcupines-hedgehogs-and-armour/14/) — The horned lizard squirts blood from its eyes, sometimes over a metre, at dogs and coyotes; the blood tastes nasty to dogs but not to birds, so it uses this only against dog-like enemies. - [15](https://md.mova.elamur.ai/free/en/corpora/school/biology/248-defences-skunks-porcupines-hedgehogs-and-armour/15/) — Crabs raise their claws to look bigger, male fiddler crabs wave one giant claw, and many crabs can grow back a lost claw over several moults. - ← previous: [Defences: poison, warning colours and mimics](https://md.mova.elamur.ai/free/en/corpora/school/biology/247-defences-poison-warning-colours-and-mimics/) - next →: [Defences: tricks and myths: playing dead, dropping tails, ink, and do ostriches bury their heads?](https://md.mova.elamur.ai/free/en/corpora/school/biology/249-defences-tricks-and-myths-playing-dead-dropping-tails-ink-and-ostriches/) - ↑ back to [Biology](https://md.mova.elamur.ai/free/en/corpora/school/biology/)