Lo Bennett age  11 of Bridgeport Conn. for his question:

Why don’t beavers eat fish?

Some animals are meat eaters and some are vegetarians. Some like ourselves, enjoy both meat and vegetables.  There is no accounting for these tastes. It is nothing to do with the size or strength of an animal   for cows, elephants and moose are strict vegetarians. Tigers and lions eat only meat and gorillas and bears eat both. Certain whales grow big on diets of meat, Other whales grow even bigger on mixed salads of seafood and sea plants,

Whatever the reason, an tin animal usually sticks very close to his chosen diet. Even if he is hungry and other diets were handy. The water loving beaver could catch as much fish as he wants. But no, he prefers to live on twigs and bark a diet on which we should probably starve. Nor can he say it improves his coat for the cuddly mink with his beautiful coat is strictly a meat eater.