Always caulk between the siding and the trim.
Seal gap between siding concrete.
Loctite pl10 often the gap to be filled is quite deep.
Look under the siding at the area meeting the foundation of your home for holes and gaps.
I believe you have tar paper under your siding based on your description.
In that case the use of backer rod before caulking is recommended.
Theoretically you could seal the tar paper to the foundation with foam spray caulking something similar.
Use a small.
Note that there are various types of caulk.
Crawl around the exterior of your home and use a flashlight to find cracks holes and gaps.
How to seal siding to keep out mice.
The urethane caulk sealants were developed for the joints between the panels in concrete tilt up construction.
Not a vapor barrier as you say but it prevents water that makes it past the siding from getting any further into the wall.
Vertical trim gap caulking.
The best solution here may be to clean up that area of all debris let it be fully dry and then apply a bead of qood quality exterior grade caulking material.
To prevent further water damage install closed cell backer rod in the gap between the patio and house foundation and cover it with concrete crack sealant.
Do not caulk between siding and any built in receiving channels located at or around windows.
Leave a 1 8 gap between the siding and the trim or other materials to allow for structural movement.
Find the entrances mice use to enter your home.
All it takes is backer rod and concrete flex sealant.
I am going to assume that you have a concrete patio which has a small gap where it meets the house foundation.
In this case what i would use is a polyurethane caulk made for masonry like this one.