Found in windowsill crawling out of click beetle (Elateridae) body that was stuck inside spider webbing. August 24, 2019 San Juan Island, WA
Carpet beetle larvae like to eat things composed of animal products (containing keratin) like wool or hair. Outdoors they like to feed on dead animals or scavenge inside animal nests. Your sweaters, carpets, and furniture items can be attractive to them and damaged if they build up in large numbers. Sometimes these beetle larvae can make people sick. Notice the many tiny hairs that cover the larva body. These are called hastisetae and can make sensitive people break out in hives or rashes if they come into contact with the larvae. The best way to keep these from building up to large numbers in your home is to vacuum often and adopt good sanitation practices.
Read more about them here: http://insectsinthecity.blogspot.com/2016/03/do-carpet-beetles-sting.html