Teachers in the Dallas area are finding a growing number of students using a cheap, heroin-laced powder -- dubbed "cheese." School officials say the stuff can be packed under fingernails and discreetly taken during class.
Cheese is a combination of trace amounts of heroin and over-the-counter cold medicine.
The items began appearing in Dallas high schools and middle schools last August.
Authorities say the tan, crumbly drug sells for as little as two bucks -- and can become addictive after just using it a few times.
Police are investigating this week's death of an 18-year-old student who witnesses say took the drug.
An official cause of death is pending.
School district officials in Houston and Austin say so far they haven't found any cheese on campus.