Cellar Spider:

Cellar spiders make delicate, tangle webs in cool, quiet corners of basements and garages. When disturbed, they vibrate rapidly in the web, blurring their outline and confusing predators. They trap mosquitoes, moths, and other indoor insects, providing free pest control with minimal mess. Populations increase where prey is plentiful and humidity is moderate. To reduce sightings, improve sealing around doors and windows, use dehumidifiers, and vacuum old webs. Because they’re harmless, relocation or simple cleanup is usually sufficient.