Bears in the Lake Tahoe area on the California-Nevada border are feasting on unlocked food, digging through household refuse and raiding refrigerators, the San Francisco Chronicle reported Friday.
"It seems like they've changed their behavior from breaking into (people's trash) to breaking into homes," said Cristen Langner, a wildlife biologist for the California Department of Fish and Game who specializes in managing the bears in the Tahoe basin.
These break-ins have led to an increase in the number of bears having to be killed, the newspaper said.
Rangers in the region have killed 11 problem bears since the end of the winter hibernation period.
The problem has been growing for years, wildlife experts say, with huge increases in the number of bears in California.
In 1984, there were 4,080 American black bears in the state, according to Fish and Game statistics. By 2008, the number had grown to 37,518, officials said.
Many mother bears in the Tahoe area have been seen with three cubs in tow. Two cubs are common for well-fed bears. Three usually means the bears are topping up on leftover human foods, the Chronicle reported.