Due to their combined smell a large group of garter snakes in or under your home can make your residence uninhabitable.
Garter snake in house siding.
While garter snakes are generally solitary creatures they generally hibernate in large numbers to prevent heat loss and keep their bodies warm.
Yards and gardens easily become their cozy homes so they can feed themselves on earthworms tadpoles insects mice lizards and other reptiles found in this area.
Gaps between siding and stone veneers brick or any similar material should be repaired to prevent moisture damage and stop snakes from gaining entry.
These are individuals that needed to be relocated.
I had a family of garter snakes living inside my siding exactly same situation as you had when i put the deck on i removed siding to attach the ledger and half a dozen snakes came out of the lower trim piece just like you describe.
Through gaps between brick and siding osborne also warns that snakes can get inside by slipping between bricks if mortar is missing and also between bricks and siding on the exterior of your home.
The most distinguishable feature of garter snake is a light shaded stripe running along its back.
Garter snakes living in vinyl siding removal.
That one does not look like any of those so most unlikely it is poisonous.
Lifting up the loose edges allows for some of the snakes to drop out.
If the affected panels of your siding are easy to remove doing so will allow the snakes a quick exit before.
They prefer to live in a warm and damp environment.