What's that sound?

It's like scratching.

And what's that noise? Squeaks?

Sounds as if you might have a raccoon in the attic. Maybe a possum. Or, heaven forbid, a skunk. But it's some kind of animal with which you do not wish to share accommodations.

What do you do?

You can try to solve the problem yourself or you can get help. But be careful. There is a bewildering network of state, county and municipal laws and regulations on dealing with wild animals.

"What is allowable depends on the municipality,'' said Jack MacRae, a naturalist at the Willowbrook Wildlife Center, 525 S. Park Blvd., Glen Ellyn.The center, operated by the Forest Preserve District of DuPage County, provides rehabilitation to native and passing migrant wildlife and education on the biological and ecosystems current and native to the area.

To find out what you can and can't do, MacRae recommends calling the animal control unit of your local police department.

La Grange residents can call the police department at 579-2333 and speak to Dispatch. La Grange Park residents can call the police department at 352-2151.

"What you want to do depends on a lot of things,'' MacRae said. "A lot depends on what type of animal you're dealing with.''

The first and most simple solution—if it works—is to drive the animal off. The wildlife center recommends several paths to pursue:

• Continuously shine bright light into the area inhabited by the animal;
• Shove ammonia-soaked rags into the animal's area;
• And, not surprisingly, blast loud rock music into the peace-loving animal's bedroom.

A detailed list of steps to take and specific tips depending on the type of animal are  available by calling the center at (630) 942-6200 or by going to willowbrookwildlife.com.

But if the animal doesn't want to leave, or actually likes the music you've blasted at him, you probably need to take stronger steps. But, again, be careful.

"Trappers need to be licensed by the state,'' MacRae said. "Before you hire anyone, make sure they are licensed by the state.''

The Illinois Department of Natural Resources (IDNR) is the agency that regulates the granting of such licenses.

You could try to capture the animal yourself, but you probably don't have a license. And even if you did capture the animal, what would you do with it? You can't kill it and you can't let it go. Such wild animals cannot be released onto public property, MacRae said.

But if you still insist on doing it yourself, contact the DNR to request an animal removal permit. A removal permit will be issued only after all other reasonable methods  have failed to correct the problem.

"We'd recommend hiring a licensed firm,'' MacRae said.

Hiring a pro is safer, too. Wild animals can cause injury. And wildlife can be carriers of disease. Professionals have the necessary licenses and permits. They also have the skill and ability to humanely euthanize animals, should that be necessary.

And professionals can transport animals safely and  securely. It is illegal to transport animals unless they are secured in an appropriately sized trap.

Some animals, mice for instance, are not covered by the Illinois Wildlife Code, so no permit is needed to trap or kill them. But it is illegal to remove or euthanize animals covered by the code without a permit. And chances are the animals you want out of your attic are on the list.

The IDNR issues such permits only if it determines that the animal is causing substantial property damage or if there is a public health or safety issue.

How do you know the professional you hire is qualified and licensed? The IDNR can provide that information. Licensed operators have a nuisance wildlife control permit issued by the department. To obtain a license, operators must pass an annual test administered by the department and must follow strict guidelines for capturing, handling and transporting animals.

To become a licensed nuisance wildlife control operator, contact Laura Kammin at lkammin@illinois.edu. She is the project coordinator for the University of Illinois Office of Sustainability.

If all of this sounds like a bother and an expense, you can always try to prevent the problem of uninvited wildlife guests in the first place. Here are tips, some are seasonal and some are good to follow year-round, for removing items that attract wildlife:

• Remove food sources such as bird seed, pet food, garbage or food scraps in compost bins.
• Remove sources of water such as bird baths, backyard ponds, leaky outdoor faucets or containers that hold rain water such as old tires or plastic food containers.
• Remove cover and shelter.
• Remove plants that are attractive to wildlife for food and shelter.
• Cut back tree limbs that are within 10 feet of buildings. Keep grass cut short (2 to 3 inches high).
• And remove brush piles and piles of stacked firewood.

You may not be willing to do all this. So, be watchful.

The University of Illinois Extension (on its Living with Urban Wildlife in Illinois website) recommends regularly checking the integrity of your home.

• Make sure the soffits and eaves of your house are in good condition.
• Install a chimney cap and use hardware wire over outside vents.
• Quickly repair any holes that you find. But make sure you don't seal the animal inside.
• Prevent animals from burrowing under decks and around foundations by placing hardware cloth over openings under decks and patios.