KELLY MCEVERS, HOST:
The trouble at West High School started on Monday. That's when students and teachers at the Salt Lake City school noticed something.
AILSA CHANG, HOST:
Bats - lots of them. Custodians found 50 on Monday. By Tuesday, there were 200. And on Wednesday after classes got out, they decided to lock down the school.
MCEVERS: Custodians looked for gaps and leaks and relocated the bats. Here's district spokesman Jason Olsen.
JASON OLSEN: They catch the bats by just using nets almost like a butterfly net. And the bats actually are fairly tame. They don't come diving at you or anything else. They actually try to get out of your way most of the time.
CHANG: Turns out bats aren't a new problem for West High School. The school was built on a bat migratory path.
OLSEN: This goes on every year about this time when the weather gets colder. We've had quite a few jokes about, you know, seeing if they could come a little bit later and - just in time for Halloween and decorations there. But we don't really control that timing.
CHANG: One more missed opportunity - the school's sports teams are not called the Bats.
MCEVERS: The West High School Panthers were back in class as usual on Thursday. Transcript provided by NPR, Copyright NPR.