Figuring out what is or isn't legal in ridding one's yard of critters is a little like sorting through all the advisories in a Viagra commercial.

"There are a lot of 'buts' involved," said Keith Streff, senior humane agent of the Animal Humane Society in Golden Valley.

First and foremost, anyone wanting to kill or trap and relocate back-yard pests should check with their local community. But in general, Streff said, standards depend on "the order of the animal."

"I don't think the method of euthanasia is scrutinized for a mosquito vs., say, a dog. There also is a difference between pets and animal wildlife."

One key, he added, is being able to demonstrate that you're dealing with "depradation animals, which is any animal about to cause harm to personal property or individuals."

The safest course is to call in a pro to deal with a problem pest. Companies such as Minnesota Nuisance Wildlife Control and Critter Control relocate thousands of animals a year. But most of the squirrel removal is from houses rather than gardens, said Critter Control's Josh Overmohle.

"If we trap squirrels from people's yards, we would charge on a per-squirrel basis," he said, "And most people when we tell them we'll be trapping all the squirrels in the neighborhood, they don't want to do that."