Keep squirrels out of a yard by fencing them out, scaring them away with another animal, or by creating an unfavorable condition that causes them to leave. Alternatively, you may trap or kill the squirrels, but local regulations may dictate whether or not this is an acceptable method of squirrel control.
If controlling squirrels by using a fence, the fence must be tall enough so that the squirrels cannot easily jump over it. Moreover, it must be buried deep enough so that the squirrels do not dig under it. Be careful when digging a fence, however, as there may be electrical lines or other utilities in the ground. If required by local law, have a survey conducted prior to digging a fence. Even with a fence installed, squirrels may still be able to climb the fence to get in the yard.
Squirrels do not go places where they feel threatened. This is why having a pet dog or cat can help control nearby squirrels. Squirrels are unlikely to approach pets because they are afraid of being eaten or chased by larger animals. If getting a cat or dog is not an option, simulated animal urine may be enough to scare squirrels away.
Squirrels also do not like getting unexpectedly sprayed with water or having bright lights unexpectedly shining on them. Because of this, automatic sprinkler systems and motion-activated lights make for great squirrel control systems.
If all else fails, contact a local exterminator to help control squirrels in the yard.