Squirrels are prey animals. In addition to their other senses, they rely on their finely tuned sense of smell to avoid danger and locate food. However, using their acute sense of smell against squirrels is one way to keep them away from your yard. Scent repellents are a form of squirrel control device available at most hardware stores.
Scent repellents come in spray and granule forms. Many scents that repel squirrels and rodents are pleasant to people.
Additionally, many non-toxic repellents are safe for people, pets, or wildlife. Common ingredients include capsaicin, cayenne pepper, garlic, pepper, and peppermint.