11/15/2024

Four-Legged Winter Invaders

By Richard D. Kramer, BCE, Kramer Pest Management and Consulting

I’ve written and read about the many six- and eight-legged critters that invade customers’ homes and businesses this time of year. However, we tend to ignore the four-legged critters that invade structures in the fall seeking winter harborage.

The first thing we need to do is understand why they do it. The first and most obvious reason is that they need a warm location to survive the cold during the winter months. The second and saddest reason is that urban expansion has forced these animals out of their native habitats and into new residential environments that destroy native harborage and food resources. This habitat depredation has even led to coyotes and bears moving into residential areas of Maryland.

Whether you choose to do wildlife management work or not you will be confronted with customers who don’t want to hear rustling in their attics or walls or see some animal hanging out on/under their deck, in their garage, or shed. Some of the largest attractions for these animals are food that they find at bird feeders, trash cans, and pet foods stored in garages. Besides structural damage and product loss, there are several other reasons to consider wildlife removal services, such as:

• Ectoparasites: fleas, ticks, and mites. Besides their blood-feeding habits they some of these parasites can transmit diseases.
• Diseases such as rabies (fox, skunk, raccoon, and feral cats).
• Fecal and urine deposits are another issue particularly when the activity persists over a long period of time.
• Nesting can cause damage to insulation, wiring, framing in attics, and roofing.
• Some animals in attics are active during the day, such as squirrels while others come and go at night such as raccoons and flying squirrels, and in the process often disrupt the occupant’s sleep.
• Customers’ fears and concerns.

The following is a brief discussion of three winter attic residents:

Flying Squirrel:

• Habits: They aggregate in winter: 4-10/nest; they glide (don’t fly) 15-75 feet; and mate 1x/year.
• Preferred foods are fungi, nuts, tree sap, insects, carrion, bird seed and pet food.
• They make a lot of noise at night.
• Management: exclusion with ¼ inch hardware cloth, stuff it, and/or xcluder. Repellents such as Nature’s Defense may be effective; there are no registered toxicants or fumigants; live trapping is challenging and, in my experience, many die anyway; snap traps are more effective.

Gray Tree Squirrel

• Biology: They can have 1-2 litters per year (2-3/litter) in spring and late summer.
• Habits: They prefer nut-bearing tree habitats where they forage for acorns, hickory nuts, walnuts, and beechnuts. They also feed on some flowering trees. They forage during the day and on warmer days are most active in the early morning and early evening.
• Management: Start with a detailed inspection and observation. It is always easier and safer to trap wildlife outside of an attic rather than inside or on a roof. Look for runs in the insulation - this can help to locate points of entry. Look for rub marks and scratch marks where animals are climbing exterior surfaces. Inspect for overhanging trees and branches. If trees are cut back, keep in mind squirrels nesting in attics leave to forage for food making trapping on the ground much easier and cost efficient. Snap traps also can be used but can raise issues with some customers. Traps can be baited with peanuts or peanut butter.

Raccoons

• Biology: Raccoons mate in January through March. They have one litter per year containing 2-5 young. The mother remains with the young until fall and then the young are on their own.
• Habits: They easily enter larger holes but will frequently enlarge smaller ones. They can be found in open nests or nests made by other animals. While attics serve as ideal nesting sites, chimneys work as well. They can readily climb up structures using downspouts, chimneys, wires and pipes.
• Trapping: Live traps can be set in the attic, on the roof, or on the ground. Setting traps in the attic can prove difficult for several reasons. For instance, carrying a large raccoon down a ladder or if the trap isn’t protected from adjoining materials, the raccoon could destroy what it can reach. This is true also of trapping on a roof – climbing down can be challenging and the trap should be mounted on a board to protect the roof. I prefer ground trapping, however the baits used may result in trapped cats or even a skunk.

Regardless of the removal, all entry points should be properly sealed to prevent reentry or other animals from taking advantage of unprotected entry points.   

If you are trapping wildlife, there are several regulations you must follow:

• You must have an MD DNR-issued permit.
• All traps must be labeled with permittee name and address or permit number.
• Traps must be checked every 24 hours - in the summer my experience is that they should be checked twice per day.
• Wildlife disposal must be one of the following:
  • Capture, exclude, and release on site, unless euthanized (this is the only option for potential rabies carriers).
  • A person, while trapping or attempting to trap animals, may not place, set, maintain, or operate any snares, body–gripping, or leghold traps within 150 yards of a permanent human residence.
  • Humane dispatch - usually using CO2. Drowning isn’t permitted.

Always check state regulations for specific requirements regarding wildlife management.

Animal removal and exclusion is ideal work for the slower winter months when many of our businesses are looking for ways to fill downtime.