Stores of FoodBecause tree squirrels don't hibernate, they put aside a supply of food to sustain them during the winter. Squirrels' primary diet consists of seeds and nuts, and they particularly love acorns. Acorns are plentiful and rich in nutrients, in addition to being small and easy to carry. They keep well when stored for long periods of time, and they are relatively soft, meaning that squirrels can eat them more quickly. All of these qualities make acorns one of a squirrel's favourite foods. If you find acorns or other seeds or nuts in your attic or on your roof and there isn't another reason for them to be there, e.g., you didn't put them there and there are no oak trees with branches overhanging your roof, chances are that squirrels are the culprits.
Strange SmellsIf squirrels are living in your attic, chances are good that they are relieving themselves up there, meaning that you may have the smell of squirrel urine. Squirrels don't look for particular places to urinate; when they have to go, they go. Squirrel urine smells strongly of ammonia, and if the rodents get into your HVAC system, the smell may circulate all through the house. If a squirrel dies inside your home, its carcass can produce another, even fouler odour as the body decomposes and gives off noxious gases.
DroppingsSquirrels are just as indiscriminate about where they defecate as where they urinate, so you may see droppings where the squirrels have been. Squirrel droppings look like small, dark pellets. Depending on the amount of moisture in a squirrel's diet, they can be hard and spindle-shaped with pointed ends, or they can be soft and clumpy. Contact with squirrel droppings can expose you to dangerous infectious diseases, such as the following: