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.
This is Dr.Christian. Chewing lice are spread from other dogs (technically they can get on you but will not stay there long-they like one species only). They chew the skin for a meal rather then suck their meal like a mosquito. The lice crawl on the skin chewing and feeding.