A joker who made a bat cave out of a dorm room, and three other students believed to have stolen the dozen or so nocturnal critters used in the caper, could be in for criminal charges, officials said Thursday. At least five University of Arkansas at Fayetteville students had been in close contact with the bats, but state epidemiologist Dr. Frank Wilson said the exposure wasn't significant enough to require rabies shots. Health officials urged anyone else who was near the bats to be evaluated.

Three students gathered the brown bats during a caving expedition at Devil's Den State Park in northwest Arkansas, said university police Lt. Gary Crain. "The bats were pretty docile; they were sleeping. It was pretty easy to pick them like apples," Crain said. After they brought the bats to campus, a fourth student "thought it would be funny to release them in someone's room," he said. After the flying mammals were set loose in the dorm room April 5, animal control officers captured them and released them back into the wild.

Crain said that far from seeking to cover their tracks, the students posted pictures of the bats on the Internet site facebook.com. "That made it a little easier for us," he said. Prosecutors are considering charges, which could include theft for taking the bats and harassment _ "at the very minimum" _ for releasing the creatures, Crain said. The Arkansas Game and Fish Commission also could pursue wildlife-related charges, he said. Three of the students are 19 and one is 20, Crain said. With no charges filed Thursday, he declined to identify them. Fayetteville animal control officials said the bats appeared to be healthy, and rangers at Devil's Den State Park said they have seen no instances of sick bats.