| Every March 19 the swallows
return to California's Mission San Juan Capistrano,
after spending the winter in Argentina. Swallows, like
all modern birds, have no teeth. They "chew" their
food by swallowing tiny bits of gravel. The gravel
chews the food internally! The last time that a bird-like
creature could actually bite was about 90 million years
ago. |
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