Bed bugs are on the rise in schools, NY1 reports. Though the city couldn’t provide any hard data on the number of infestations, officials told the station that the bed bug problem has gotten worse as the hard-to-exterminate critters have become more common.

The city will only send exterminators to a school after a dead bed bug has been mailed to a lab — but parents and bed bug experts like American Museum of Natural History entomologist Lou Sorkin say that schools need to plan ahead. "They should be proactive. Maybe give the students large ziplocked bags in which they can place their clothing and book bags. And if children have infestations, they should be told about it and then their parents can do something about it," said Sorkin.

Though the Department of Education doesn't provide schools with seal-able plastic bags, the PTA and teachers at PS 163 — an Upper West Side school that has been infested with bed bugs multiple times in the past year — have shelled out for the bags so students and teachers can seal up their belongings three times per day. The bags were costly, but parents and teachers hope they'll stop the bugs from traveling between the school and students' homes, meaning neither the city nor parents will have to pay costly extermination fees.