Hiding behind your curtains, burrowing under your bed, and taking over your bedroom are millions of teeny tiny dust mites. These microscopic creatures take root in the cozy parts of our homes, such as our bedrooms, and could be the culprit behind some of your spring and summer allergies.

If you often have a runny nose when you wake up in the morning or you get allergy attacks at home, making this one change to your bedroom could help. But be warned: if you are easily grossed out, you may want to stop reading now.

What are dust mites?

Dust mites have eight legs like spiders and are approximately one-quarter of a millimeter long, according to the Asthma and Allergy Foundation of America. They gather in soft areas of our homes, like furniture, bedding and curtains, where they feast on flecks of human skin that we naturally shed throughout the day. The thought of invisible spider-like creatures crawling all over curtains and bedding and eating human skin should be enough to make you pull out your vacuum.

“Dust mites eat shed human skin; that’s their favorite food,” Dr. Manav Singla, allergist with MedStar Health, told HuffPost. “So anywhere skin cells can collect, anywhere shed human skin and animal skin collects, is where the dust mites are going to eat them and live.” This includes fibers found in carpets, mattresses, pillows, comforters, stuffed animals and curtains.