Why do squirrels and raccoons move into attics in winter?
Cold nights make a dry, insulated attic far more attractive than a tree hollow. Wooded lots and lakeshore properties have plenty of animals nearby, and a loose soffit or open chimney is an easy way in. Calls tend to rise in cold months and again in late winter when litters are born.
An attic holds the warmth that rises from the house and is sheltered from snow and wind. To a squirrel it is a ready-made den.
Animals return to the same spot each year. Once one has used an opening, it is marked by scent, and it will be tried again.
Is it safe to wait until spring?
It is better not to. Animals in an attic can damage insulation, wiring and wood, and they may be raising young. In winter they can be removed quickly. Waiting until spring risks a litter in the walls, and a longer, harder removal.
Chewed wires are a fire risk, and wet insulation loses its value. The longer an animal stays, the more cleanup there will be.
Do not seal the hole yourself while the animal is inside. It will chew a new one, often through a ceiling.
What can I do about the tree branches?
Trim branches back from the roof by several feet so animals cannot jump across, and fit metal collars to trunks where practical. Trimming helps but is not enough on its own, because squirrels can climb walls and wires. Sealing the openings is the permanent fix.
Overhanging limbs are the highway. A branch that touches the roof is an open invitation.
If the tree is a neighbor's, ask politely. If the work is high, hire an arborist rather than climbing.
What happens to the insulation and droppings?
Droppings and urine-soaked insulation can carry odor, parasites and disease risks, so they should be handled with protection and often removed. A technician can advise on clean-up or refer you to a specialist. Do not disturb a raccoon latrine without a mask and gloves.
Raccoons often use one spot repeatedly. The spot should be cleaned carefully and the material bagged.
If the insulation is flattened and stained, it has lost most of its benefit and may be worth replacing while the attic is open.
Does a squirrel in the attic mean mice too?
Not necessarily, but the two often share an attic because the same gaps and warmth suit both. Scratching at dawn points to squirrels, while light scurrying at night suggests mice. A technician checks droppings and tracks to tell them apart and plans for both if needed.
Mice can use the same insulation tunnels that a squirrel leaves behind. A clean-up and seal that addresses the larger animal's opening may leave smaller gaps open.
Our mouse control page explains how the smaller animals are handled, and the technician can combine both jobs in one visit.
