age baby squirrels begin leaving nest
1 It is best to wait until the baby squirrels are 10 to 12 weeks old when they will leave the nest on their own in search of their own territory. 2  In the meantime, pay close attention to how the squirrels get in and out.f the mother has still not returned for her baby, contact your nearest wildlife rehabilitator. 1  In a tree that was just cut down? 2  Check to see if the baby squirrels are ok. 3  In my house or attic? 4  It is best to wait until the baby squirrels are 10 to 12 weeks old when they will leave the nest on their own in search of their own territory.