Found in a trash can
Midwest USA - found these while cleaning an elderly relative's house. They were stuck to a trash can lid, both inside and out. There were definitely gnats or some other small winged insects flying around, too. I'm guessing they're not uncommon - just want to make sure they're not something where I need to immediately jump in a tub of disinfectant or something. There are also pets in the household.
Thank you!