Welcome warmer weather often brings uninvited guests: household pests.

Before you hire an exterminator to handle your bug or mice problem, learn what you can do yourself. With the exception of termites and bedbugs, you should be able to cure most infestations without the services of an expensive professional.

Some steps to take for specific pests:

Ants

If you can locate the ants' nest, spray it with insecticide. If the nest is outside, follow the ants' movements to and from food sources. If the nest is inside walls or otherwise inaccessible, cut off the paths ants follow by caulking cracks and crevices. Also try using baits like Terro Liquid. Place "bait stations" in many locations where ants can easily find them but that aren't accessible to children and pets.

Carpenter ants

They are drawn to damp wood, so you'll need to prevent water from accumulating in your house. Clean your gutters and downspouts and cut tree limbs and shrubs that overhang your house.

Cockroaches

Keeping your home clean and dry is the first step. Caulk to seal cracks and other entry points. You can try sticky traps or bait stations. Sticky traps probably won't solve an infestation, but bait stations can stomp out a small one, though it might take a week because they dispense slow-acting poison. Boric acid is another effective roach killer. Blow it into cracks and crevices where people won't come into contact with it.

Mice and rats

Close off openings more than ¼ inch in size through foundation cracks, around door and window frames and elsewhere. After closing entry points, you might be able to bring a small infestation under control with traps (peanut butter is an effective bait). Place traps perpendicular to walls, with trigger ends toward the wall so rodents will run over them. Large infestations will require poison baits, which are usually anticoagulants. Be careful to place them out of reach of pets and children.

Bedbugs and termites

They're the most problematic pests. Bedbugs are notoriously difficult to control. Since sanitation won't prevent bedbugs or get rid of them, you'll likely need to hire a diligent, experienced exterminator, and you will probably need a series of treatments. Your best bet is to contract with a company to perform a rigorous initial treatment and follow up with scheduled inspections and re-treatments for a year.

Most pests are unpleasant, but termites can wreck your house. If you hire an exterminator, be wary of operators who push bait systems. Because the bait stakes used to monitor termite activity are designed to attract termites, sticking several in the ground around the perimeter of your home probably will attract termites. These companies will require an expensive long-term contract to monitor the bait stations, and once the stations have done their job, the companies might use the evidence of infestation to sell you a warranty against future infestations.

Exterminator

Be wary and skeptical of any pest control service or product that markets itself as green. Checkbook has found that many companies that claim to provide natural solutions employ the same pesticides and methods used in conventional treatments.

Even if a pest control method is labeled "natural" or "non-synthetic," read the product safety label carefully. Companies should supply them upon request. To learn about a pesticide, check the EPA's pesticide selector website at epa.gov/insect-repellents/find-repellent-right-you. If you find a notice that an EPA review is underway — or that researchers or citizens' groups are urging one — it's a red flag.

If you decide to hire a pest control service, shop around. Checkbook found big company-to-company differences when it asked area consumers to rate pest control services they had used. Some outfits earned a rating of "superior" overall by 90% or more of their surveyed customers. But other companies received such favorable ratings from fewer than half of their surveyed customers.

If you're ready to call in a swat team, Checkbook.org's ratings of local pest control services for quality and price can help you find one that will do the job right for a fair price. Until May 5, Minnesota Star Tribune readers can access Checkbook's report free via Checkbook.org/StarTribune/pests.

Final advice

Get multiple estimates and beware of annual contracts that cost hundreds of dollars. For most pests, a single treatment done well should suffice.

If you think you have termites or bedbugs, it's especially important to field several proposals. For termites, ask whether the service recommends treating only part of your home or its entire perimeter: You'll save big if a company can wipe out your infestation without a house-wide treatment. To treat a small termite infestation, companies quoted prices ranging from $1,000 to more than $3,000 to Checkbook's undercover shoppers.

Get any company guarantee in writing and check what it offers: Will the company pay for additional pest damages or just re-treatment? How often will it come out to inspect at no extra charge? And what do you have to do to keep the guarantee in effect?

Twin Cities Consumers' Checkbook magazine and Checkbook.org is a nonprofit organization with a mission to help consumers get the best service and lowest prices. We are supported by consumers and take no money from the service providers we evaluate. You can access Checkbook's ratings of local pest control services until May 5 at Checkbook.org/StarTribune/pests.