A window screen will not stop a hungry black bear.
At least it didn't several years ago on the north edge of La Grande.
A black bear knocked down a screen window on a backyard porch and crawled in to get some food a family had not put away.
The chances of this happening are often greatest in late summer and early fall when bears are feeding voraciously in preparation for winter hibernation, said Oregon Department of Fish and Wildlife Biologist Leonard Erickson.
Bears are often more aggressive now when searching for food and are more likely to go into people's yards while foraging.
The people most likely to be victimized are those who leave dog food, horse pellets and unsealed garbage cans outside. People with fruit trees and compost piles also run the risk of attracting bears. Compost piles are particularly attractive if they contain sugary treats like donuts and old fruit.
Keeping bears away is often as easy as taking simple prevention steps.
"If you don't create an attraction, they will have no reason to stay and will move on,'' Erickson said.
The biologist said he has had only a few calls this fall from people complaining about bear damage. This may reflect that there is a good crop of fall fruit for bears to feed on in the Grande Ronde Valley. These include huckleberries, apples and elderberries.
"Bears will stick to natural food if they have a good supply,'' Erickson said
Some people with bee hives are afraid of bears coming in and taking their honey. The best way to prevent this is to put electric fencing around the hives.
"They won't try again (to get through a fence) after being shocked,'' Erickson said.
Bears generally only bother homes in the country or on the outer edges of a town. Occasionally they venture deeper than expected into town. For example, in 1999 a black bear came regularly into the C Street area to feed on apple and plum trees.
The visitor often appeared agitated and was not shy about showing up in the daytime. Normally black bears leave populated areas then.
Although the bear was not threatening anyone, it did pose a danger to people in the neighborhood and so was killed by the ODFW on Sept. 16, 1999.
According to the ODFW Web site, the agency generally does not relocate bears that regularity come into populated areas because of safety concerns. Research indicates that relocating problem bears does not work. Bears have been known to travel great distances to return to their home range.
"If a relocated bear stays away from its original home range, it often will seek human foods in its new habitat or move to an area where human food is available,'' the ODFW says.
If the ODFW has to trap a bear, the bear will likely be euthanized.