In rescue situations such as from chimneys or basements, on-site release of squirrels is recommended, provided the entrance has been secured.
Tree squirrels should not be translocated because of the stress placed on both transported and resident squirrels, and concerns regarding the transmission of diseases. Many states do not allow the translocation of squirrels. Check with your local wildlife agency.
Carbon dioxide is the preferred method of euthanasia for tree squirrels. Squirrels expire relatively quickly in a rich carbon-dioxide environment.
Check your state regulations regarding disposal of carcasses.