Ald. Matthew O'Shea, of the 19th Ward, released a community alert Saturday, saying the bat was first spotted near 99th and Hoyne earlier this week.
O'Shea advised residents not to handle any bats or wild animals.
Residents were also urged to keep their pets on a leash when they're outside, and make sure they are up to date on rabies vaccinations.
If any bats are found, residents should call 3-1-1 to report it to the city's Animal Care and Control.