A vicious squirrel sent a subway operator to the hospital on Wednesday, transit sources said.

The 24-year transit veteran from the Bronx was bitten about 4:30 p.m. at the Woodlawn station in the Norwood section of the borough.

A source said the wayward squirrel attacked the train motorwoman while she was going up the stairs at the stop.

She was treated at Montefiore Hospital for the wound.

The train operator began working for the MTA in 1991.