A glimpse of a woodpecker on a lunchtime walk turned out to be a male yellow-bellied sapsucker, working through an already marked tree. The sapsucker 'wells' are used primarily to trap insects, which are consumed, but secondarily serve other birds, such as ruby-throated hummingbirds, and probably insects, etc.
Hummingbirds track the sapsuckers on their northern migration. The sapsuckers are still here (they're winter residents), and the ruby-throated hummingbirds have been seen in Texas.
But spring migration is on the way.