Most people know that rats are members of the rodent family, though few realize that rats and squirrels are closely related. In fact, rats and squirrels have a number of similarities: Both pests must constantly gnaw on wood and other items to wear down their ever-growing teeth. Tree squirrels are known for their bushy tails, while rat tails are notoriously scaly. Their diets are quite similar, as both are omnivores. Though the two pests have similar habits as well as habitats, telling them apart is crucial to successful removal from the home.