Frogs and toads can breathe through their skin. When a frog is in the water, its skin absorbs some of the water. The frog gets oxygen from the water. But the frog also absorbs any pollution that may be in the water.
Endangered animals are close to being gone from the world. When an animal is completely gone, it is extinct.
When an animal migrates, it moves from one place to another during the year. Many birds migrate in the fall and spring.
When an animal looks like what is around it, it is camouflaged. Frogs are good at camouflage. Some frogs look like leaves, bark, moss, or even bird poop!
Penguins need lots of fish to eat. If people catch too many fish, penguins will not have enough food.