A plastic baggie filled with bed bugs was found in a Des Moines city building a few weeks ago and it’s prompted an expensive extermination effort. Custodians came across the bagful of bugs but not before the creepy crawlers infested what’s known as the Des Moines Armory.

It houses several city departments like Human Rights, Information Technology and Community Development. The building was fumigated three times already and the biting bed bugs are still there. Officials say it’s possible the bag was dropped intentionally by someone seeking revenge against the city.

The fumigations totalled $1,200. Since that tactic didn’t work, the next step is super-heating the building to 140-degrees which should kill the bugs this weekend. That’s expected to cost another $5,000.