Ants
Ants evolved from earlier wasps about 150 million years ago, around the same time that mammals were beginning to become common. Some wasps lost their wings and couldn't fly anymore, and some of those evolved into ants (though a few kinds of ants can still fly a little, and some wasps can't fly). Some ants have even lost their eyes because they live underground and don't use them.
Ants evolved in order to eat the grass-eating insects, like grasshoppers, that evolved to eat the new flowering plants about 100 million years ago.
But soon ants had predators of their own: birds, which evolved to be able to eat ants.
To find out more about insects and crabs, check out these books from Amazon.com or from your library:
