There's a fun mystery going on at an Iowa elementary school.
Someone's been dropping off rubber ducks every day since the start of the school year.
"... Was putting away books, and we just found a random duck. And we didn't really think anything about it," Mark Twain Elementary Liberian Erin Waldron-Smith said.
Until it happened the next day and then the day after that.
"At first, they were easy to find, and then they got harder and harder, and they started to multiply," Mark Twain Elementary Liberian Erin Waldron-Smith said.
By this point, ducks are on the ceiling lights, desks, and bookshelves.
Now the school is getting easter eggs with a duck-themed puzzle piece inside.
Everyone hopes it'll reveal the identity of who's leaving the ducks.