 
 quirrels breed once or twice a year and give birth to a varying number  of young after three to six weeks, depending on species. The young are  born naked, toothless, and blind. In most species of squirrel, only the  female looks after the young, which are weaned at around six to ten weeks of age and become sexually mature at the end  of their first year. Ground-dwelling species are generally social  animals, often living in well-developed colonies, but the tree-dwelling  species are more solitary
