Many plains people survived off cattle, buffalo, deer. Many coastal/lake/river peoples survived off fish. Many people have used domesticated chickens, ducks and other fowl to produce eggs. Some mountain people and African tribes live almost exclusively off of milk from cows, goats, sheep, yak, reindeer or mares

I've never heard of a tribe living almost exclusively off of reptiles/amphibians/insects even though I know people throughout the world do consume all of the above.

If not? Why?