I'm looking into build bat houses and water proofing the enclosure is a large part of most tutorials. Almost all suggest that you need to caulk all the seams.
None however are very specific on the type of caulk. To be clear I am not looking for brand recommendations as those would be clearly off topic. I am however looking for suggestions of the best type of caulk. Obviously I would not want to be using bathroom caulk outdoors. Last I checked there were oodles of choices.
I live in southern Canada so temperature would be a factor.