It's a lesson University of Texas at San Antonio students aren't learning in the classroom, but in their bed sheets.
The university sent out emails to notify all students that bed bugs were found in another residence hall.
Officials say this is the fourth time the critters have been found on campus at halls including University Oaks, Chisholm Hall and now Laurel Village.
Officials are now turning up the heat to bake the bugs and say they're taking more measures to exterminate the pests, including replacing mattresses and carpet.
"Remediation of a potential bed bug problem is a lot easier early on than later," said David Gabler, spokesman UTSA.
The university is urging all students to report any unexplained rashes or small dirt specs in their beds and furniture.