A&M athletic director Bill Byrne said Saturday manure went "from one end to the other" inside one bus that couldn't be locked. The others had manure along the exterior. He tweeted that the outsides of all the buses had vulgarities "spray painted" on them.
"Classy," ended his first tweet.
It wasn't immediately clear why vandals targeted Texas A&M, though the Aggies are planning to leave the Big 12 after this school year for the SEC.
Texas A&M assistant police chief Mike Ragan, who's in charge of security when the Aggies travel to away games, issued a statement saying that the buses were peppered with Texas Tech logos in addition to profanities.
"Late Friday night or early Saturday morning, Texas Tech logos and some derogatory comments were written on the buses in washable paint," Ragan said.
The Aggies were accompanied by school security and a Texas Department of Public Safety trooper and no official report was made to the agency, an email from Aggies spokesman Brad Marquardt said.
Texas Tech AD Kirby Hocutt called the vandalism "unfortunate" and that it doesn't "represent who we are as a group."
The Red Raiders lost 45-40 to the No. 24 Aggies on Saturday night.
Information from The Associated Press was used in this report.