Hundreds of birds from Indiana to Virginia have been dying from a mysterious illness, leaving scientists befuddled and asking for the public’s help.

People in Indiana, Kentucky, Ohio, West Virginia, Maryland, Washington, D.C. and Virginia have been asked to alert local wildlife officials when they come across dead songbirds, NBC News reported.

The birds have appeared blind from their unknown ailment, with crusty eyes that ooze curious discharges, according to the Washington Post. The birds have also been acting bizarrely, tilting their heads and not moving when approached.

“They’ll just sit still, often kind of shaking,” Kentucky biologist Kate Slankard told NBC News. “It’s pretty safe to say that hundreds of birds in the state have had this problem.”

Scientists, working together across the states, are still trying to figure out why so many birds are dropping dead, but some believe a new infectious disease is to blame. James Brindle, a spokesman for Indiana’s natural resources department, told NBC News that the dead birds in the Hoosier State tested negative for avian influenza and West Nile virus.

Officials have asked people to take bird feeders inside because any disease could spread easily at a crowded feeder.

People are advised to not pick up or otherwise handle dead birds. Anyone who decides to ignore that advice should wear protective gear to avoid their own potential sickness, officials said. But they noted there is not yet any evidence the disease could be transmitted to humans.