Both mice and rats are athletic and known for their ability to easily get inside of structures. Rats in particular are excellent climbers and rats can jump from overhanging trees to access roof lines and attics. Mice can squeeze through a hole the size of a dime and rats only need a gap the size of a quarter. Rodents enter homes using gaps around dryer vents, utility pipes, exterior doors, and garage doors, and will also gain entry through chimneys.