Squirrels or Groundhogs could be causing the problem
The Best Way To Identify Which Animal You Have Is By Looking For Tracks
Identifying an animal using tracks can be difficult indoors. If you know where the critters are wreaking havoc in your home, place a board in the affected area, such as an attic, and dust the board with cornstarch. If the animal walks through the cornstarch, the prints will be clearly visible, helping you to identify the nuisance pest.
