What is in my basement?

It's a House Wren nesting. Don't block any access point beyond what's normally blocked. Couple weeks they'll be gone.

House Wren
Funny thing, but today I heard a wren trying to nest around one of our outdoor garage lights. Made the exact same sound as the OPs video. It caught my attention while I was in the garage and I went outside around the back of the house and spied it in action working the nest in around the back of the light.

I would have pulled the nest down for fear of fire, it we use low wattage bulbs in those lights that won’t be overheated by the nest...so I figured I would just let them be and stay warm for the Winter.

I like wrens, they are great bug catchers and having them around is beneficial.