On Sept. 12, beloved jam band Goose played Chicago’s Salt Shed, a warehouse-turned-music-venue. Now, the city’s health department is warning concertgoers that they might have been exposed to bats.

“If you attended the concert and were bitten or scratched by a bat, or if you had direct contact with a bat, contact a healthcare provider as soon as possible to discuss rabies post-exposure prophylaxis (PEP),” a release from the city says. However, bite marks from bats are hard to detect, due to the smallness of the animal’s teeth.

“If you attended the concert but did not have contact with a bat, then there are no further actions that you need to take,” the release continues. “A bat flying above you is not a risk for rabies.”

A few months ago, the Pretty Reckless’ Taylor Momsen was bit by a bat onstage while singing “Witches Burn.”