Please use the help flairs for your help needed posts.
http://www.squirrelrehabilitation.com/found%20baby.htm
This gives some good pointers for immediate assessment of the situation.
If the baby is dehydrated, dirty, cold, thin with loose looking skin, has any fly eggs or any injuries, even a tiny scratch, then s/he should be taken in for care. If the baby was being played with by a cat or if a cat was sitting over the baby looking like s/he might have been playing with the baby, then the baby squirrel should be taken in because antibiotics are required to treat even tiny cat bites and scratches that might not be visible at first glance. Cat saliva is extremely toxic and often causes lethal infections, even in tiny amounts.
If the baby is plump/muscular, warm, well groomed and active, then s/he probably just squirmed out of bed, and the reuniting protocol should be followed.
If the baby has fallen due to a severe storm and is wet, then they should be taken in, warmed and hydrated. If the weather improves markedly the next day, you can return to the same area and try the reuniting protocol.
If it was a tree felling, and the tree in which the babies lived was felled with them in it, then try the reuniting protocol as mom may come back when the scary workers are gone, provided she is still alive.
Please make a post about the baby and please include photos in your post, but since it takes some time for people to check in and reply, start reading the links under infants/found babies sections in the website posted above in the meantime.
Also, Here is a list that one of our members made of how to find a registered wildlife rehabilitator in the US. If you call, make sure that they don't euthanize so-called invasive squirrel species and will attempt care before taking that last resort. https://www.reddit.com/r/squirrels/comments/eknkw0/here_is_an_alphabetical_list_of_wildlife/
