The pitter-patter of little feet is a welcome sound when it comes from a child's bedroom. If it comes from the attic, you've got a problem -- a wildlife problem.

Squirrels in the attic or a raccoon in a chimney can quickly become a nightmare that requires professional assistance. The Pennsylvania Game Commission might seem the obvious source of help, but Game Commission personnel deal only with large animals such as deer and bears.

"If we had to deal with every wildlife complaint we get, that's all we'd do," said Jerry Feaser, spokesman for the Pennsylvania Game Commission. "Instead, we license independent nuisance wildlife control agents."

Certification requires passing a rigorous exam that covers wildlife biology, laws and regulations regarding humane disposal of captured pests.

"These agents are highly trained and usually listed in the Yellow Pages," said Feaser. "Exterminators who specialize in insect pests may not be licensed to deal with vertebrate animals."

One such business in the Pittsburgh area is Critter Control, a national franchise with offices all across the country.

Steve Majetich owns two Critter Control offices and has been with the company for 21 years. A graduate of Slippery Rock University with a degree in environmental resource management, Majetich said he values the expertise and training he and his staff receive annually from the franchise's corporate office.

"We receive training two or three times a year to keep us current with new techniques," he said.

In the wildlife damage-control business, spring is the busiest time of year.

"Baby animals leave the den, and, if they are living in someone's attic or basement, they're hard to ignore," Majetich said.

Squirrels and raccoons account for a majority of Majetich's business. Squirrels like to nest in attics, while raccoons seem to favor chimneys.

"After the young leave the nest, they are harder to catch," he says, "so we prefer to catch family groups still dependent on the mother."

Bats also can be a problem, though Game Commission regulations do not permit them to be captured. Instead, when a colony is discovered in an attic or barn, one-way check valves are installed over the primary entrances to the building. Bats can leave the building, but they cannot return, so they must find a new roost site.

If individual bats are captured inside a home, they are euthanized, and Game Commission agents have them tested for rabies and White-Nose Syndrome.

Pigeons are another common pest, but eliminating them is virtually impossible.

"What we do, however, is install scare devices and barrier spikes that physically prevent pigeons from perching on roofs and ledges," said Majetich. "On big commercial jobs, we exclude pigeons by installing a system of nets."

Sometimes a job can surprise even the experts. Majetich recalls a mid-winter job in Westmoreland County a few years ago.

"A woman called and said she heard something running around the attic at night," he says. "We immediately suspected flying squirrels because they are nocturnal, so we visited the home, completed our initial exterior inspection and identified the points of entry. Then we sealed all the entry holes except one. On that one we installed a one-way repeating trap. The next morning there were 17 flying squirrels in the trap. On the second morning, we caught 18 more. Problem solved."

Here's where an understanding of wildlife biology comes in handy.

"My team knows that flying squirrels are extremely social and live in multiple family groups in winter," Majetich said. "I knew we'd catch several flying squirrels, but 35 in two nights surprised even me."

Majetich also points out that all his employees are capable carpenters. They seal holes and make repairs to insure that problem animals do not return.

"It's silly to remove a squirrel or raccoon and not seal all the entry points." he said. "We also clean gutters. People don't realize that clogged gutters cause water to back up and rot out fascia boards. This is often how squirrels get into attics in the first place."

One of Majetich's mantras is that prevention is the key to minimizing wildlife damage. At the very least, he says, "All chimneys should be capped, and all dryer and attic vents screened."