Things You'll Need
Instructions
Locate the nest. The squirrel will have most likely used the insulation material in your attic in its construction. Be careful not to disturb it, as the nest may contain very delicate newborn squirrels.
Place a radio tuned to an all-talk station roughly 6 feet from the nest. Turn it on and leave it turned on. This will have the effect of threatening the squirrel's sense of security and causing it to begin preparing to relocate.
Tie a number of rags together into a ball with twine. Soak the ball of rags in ammonia and place them next to the nest. The powerful smell will act as a repellant.
Leave the radio and rags in place overnight. By the next day, the squirrel will most likely have built a new nest elsewhere and moved any babies it may have -- along with itself -- to its new dwelling. The nest can now be safely disposed of.
Seal up any holes you find in the attic to prevent further intrusion. Bear in mind that a squirrel can get through a hole that is much smaller than you may think. Essentially, anywhere you can see sunlight shining in is a hole that needs to be sealed.