There's something in the water — and it isn't an ice cube. Residents of one small Oklahoma town are being ordered to sip exclusively bottled water, after tiny red blood worms started popping up in drinking glasses earlier this week.

The outbreak in Colcord, OK, has all but shut down the community, home to around 800 people. Schools are closed, convenience stores can't serve fountain sodas, and residents have been instructed not to cook or brush their teeth using tap water. Bathing, fortunately, is still deemed acceptable by local health authorities.

"The chlorine won't kill them, the bleach won't kill them."

Blood worms — actually the larvae of the midge fly — are typically small, maxing out at around half-an-inch in length. They're known to pop up in the southeastern United States, though not often in municipal water supplies, and are also sold freeze-dried as fish food. Blood worms tend to thrive in low-oxygen or heavily polluted water, where they burrow inside mud. And unfortunately for officials in Colcord, the buggers are also extremely resilient. "The chlorine won't kill them, the bleach won't kill them," Cody Gibby, the town's water commissioner, told a local TV network. "You can take the worms out of the filter system and put them in a straight cup of bleach and leave them in there for about four hours, and they still won't die."

The health risks associated with ingesting blood worms are unknown, though they aren't believed to cause adverse effects. But local authorities in Colcord aren't taking any chances — while they try to figure out how the worms infiltrated water supplies in the first place, they're also distributing pallets of bottled water to residents.