Explanation:
birds= hollow bone structure 4 flight. scales on (feet), defined as "raptors" flight feathers, thicker core for uplift, shape of beak 4 food it eats.
fish= natural "slime coat" to protect scales from water or pollution damage, have gills 2 absorb o2 from h2o, streamlined 2 swim in h2o, find to turn, dart, escape predators.
reptiles= cold- blooded, have 2 bask in sun so it can stay warm at night, eats bugs, other reptiles 4 nourishment, can sometimes change color 2 match its surroundings, or has color of surroundings.
amphibians = aquatic usually, needs moisture, goes thru metamorphosis, egg, tadpole, frog (both land & h2o bearing.
insects= eat other insects or foliage, lay eggs on leaves, hibernate or die in cold weather, butterflies make cocoons 4 next generation.
mammals= warm blooded, have sex with 1 mate or many, gives birth, usually are preyed upon by predators ( lion, tiger, etc...) hope this helps, good luck!