The Essex County Library branch in Leamington said the mystery culprit has urinated on the stacks several times during the past three weeks, most recently Monday, and each time damaged between 30 and 90 books, the Toronto Star reported Wednesday.
"As soon as they've been touched with a biohazard ... we would not circulate them to the public, they're destroyed," said Janet Woodbridge, chief librarian and chief executive officer of the Essex County Libraries. "You can't recover books."
Ontario Provincial Police have opened an investigation and library officials said security cameras will be installed in the coming weeks.
Texas principal bans speaking Spanish, stirs controversy
Exploding whale video goes viral on Internet