As summer approaches many Calgarians are finding that squirrels, birds and other critters are starting to find homes in their backyards.

Pest control companies are having a hard time keeping up.

"When you look at a pest, you're looking at their reproduction rates and their habits," said Nicholas Holland, who owns a pest control company in the city.

"Many times it isn't as simple as perhaps wanting to eliminate a pest, but a more realistic approach is to push them off the structure on to another structure."

But some avid housekeepers may be surprised what animals Albertans can exterminate legally.

Alberta Fish and Wildlife has compiled a list, which includes 60 animals from pigeons to bats to sparrows to white-tailed jackrabbits.

Some pests, like bats, raccoons and skunks can not be exterminated, but rather relocated to another area. In Alberta, pests are defined as "an animal, bird, insect, plant or disease is destroying or harming or is likely to destroy or harm any land, livestock or property."

Conservation officers and biologists make the list based on pest populations.

If an animal is classified as a pest then no licence is needed to remove it from a property. However, people are encouraged to contact a Fish and Wildlife officer for advice on the legal methods that can be used to remove it.

Non-licence animals can also be hunted throughout the year.

But Nicola Murphy, site manager for the Calgary Wildlife Rehabilitation Society, says people in an urban environment have to practice patience.

"Respect goes both ways. We need to understand their living conditions, our living conditions, and try and live in harmony," she said.

Murphy says they rescue more than 2,000 animals during the summer months.