Bears - Sounds Wild
Grizzly Bears Eat Bugs

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Grizzly bears eat bugs

On a cool summer morning on a beach in Glacier Bay, we come across a log that's been torn up by a bear. In the beach grass well above the high tide mark, the log is riddled with tunnels excavated in the wood by beetle grubs. Long claw marks striate the wood, clearly showing how the bear raked into the log and tore apart the wood.

Insects are an important part of bears' diet. Beekeepers have noted that bears raiding hives will target the bees and bee larvae as well as the honey - and sometimes they prefer the insects to the honey.

In the Rocky Mountains, a common moth known as the miller is the adult form of the army cutworm caterpillar. Hundreds of thousands of these army cutworm moths can be found concentrated on talus slopes, hiding under rocks. Researchers in Yellowstone National park have documented dozens of grizzly bears - and occasional black bears as well - converging on these talus slopes in summer, turning over rocks to eat the moths. One researcher compared the sites to salmon streams. "We've seen bears feeding within several hundred yards of each other and they seem to tolerate each other."

The moths are a very high-quality food. They are rich in fat. Bears have been documented eating as many as 40,000 moths in a day - which provides 20,000 calories.