July 16 (UPI) -- A worker at a Houston high rise captured video of an unusual sight outside one of the building's windows -- dozens of bats gathered in a swarm on the wall.
Dave Rojas, who works in an office at the building, tweeted a video showing dozens of bats gathered together to roost right outside a window.
Rojas said the building is an annual hub of bat activity.
"Every year the bats make a visit to our office. It must be that time of the year again. I think they are migrating," he wrote.