As soon as they think there may be an unwanted critter in the structure or on the property. Addressing the issue early will limit the damage and (hopefully!) make the solution less costly.
Squirrels have the ability to chew through and raccoons can tear off most building materials to access an attic space. Sturdy metal (like steel) is typically the most versatile and structural sound exclusion material to use for these animals.
Running, walking, or scratching noises in the attic or walls. Small droppings that accumulate in a localized area in the spring and summer and continue to accumulate after they are cleaned up.
Many animals (like bats, groundhogs, and snakes) hibernate in our area, making winter a much slower season for us.
Our most common issues are bats, squirrels, and raccoons in the attic. Birds in vents. Moles in the yard.