A sea lion named Diego vomited up a child's sock on Monday morning, causing a stir at a Utah zoo.

“Friends, animals can die from eating foreign objects,” the zoo said in a note on Facebook. “PLEASE keep very careful track of your belongings" near animals' enclosures.

Diego threw up blood along with the wayward footwear, the zoo said.

Zoo officials, as reported by Fox 13 Salt Lake City, urged visitors to kep close track of their socks, gloves, flip-flops and phones.

“Do not feel too embarrassed to let us know,” the zoo said. “We can retrieve the item if we know about it.”