Washington school officials cannot solve the mystery of why their building became a bat haven

Between September 14 and October 1, eight bats – six live and two dead – have been found inside Edgerton Elementary School in Puyallup, Washington, and officials still don't know how they got in - (AFP/Getty)

At least some of the Halloween decorations are alive at one Washington elementary school – but officials still can't figure out how the bats keep getting inside.

Eight bats have been found at Edgerton Elementary School in Puyallup, about 10 miles southeast of Tacoma, over 17 days. The latest was a dead one found Thursday in a mechanical room by district maintenance staff, according to the Puyallup School District's Bat Activity Tracker.