Corals are made up of tiny animals known as polyps. Each of the polyps has a skeleton cup, tentacles with stinging cells, a mouth and a stomach. Algae grow in the stomach lining and supply calcium which the polyp uses to build the skeleton cup. Here's a neat model of a coral polyp your students can make.
Chewing lice are not as common as fleas and ticks, but just as itchy and annoying. Learn about the different types of lice out there and how to protect your pets. While lice may not be as common as fleas, they can still cause aggravation in some animals, especially animals who are very young, old, or sick. There are two types of lice that affect cats and dogs: sucking lice (which suck blood) and chewing lice. Chewing lice are tiny, flat, wingless insects that feed on the dead skin of pets.
When you look closely at a cat who's been infested, fleas will present as jumpy black dots and leave a trail of black dirt. Lice, on the other hand, are white, and it's usually the eggs -- sticky white dots stuck to the hair near the skin -- that can be spotted more easily. Symptoms and Diagnosis. If your cat has lice, he might not seem too agitated, so it can be hard to diagnose the problem. In general, fleas make cats itchier and more uncomfortable than lice do. A heavy lice infestation could lead to a scruffy, unkempt look, and excessive scratching can lead to raw or bald patches.