God…I fought with my rats forever:
I am now a bit of a lay expert.
-1) They couldn’t care less about the heat, especially if it is a choice between safe, free hotel accommodations and being eaten by something else.
-2) Once they are in, especially in force, there is rarely a time they are not inside, although they go out every night.
-3) Best way to get a handle on their behavior and activity is with motion sensitive cameras. Here’s one of my guys tap dancing around all of the traps I’d set, not a care in the world:
-4) You have to block off ALL access, then trap, not poison them. You only know you have blocked off all access when you are actively trapping them and finally cameras stop detecting activity after several days.
-5) Once cameras are set, try an notice were they tend to come from/go to in evening and a.m. They will usually nest right near their ingress/egress points, but will scout all over the attic before they go out for the night and then when the come back.
-6) Rats are neophobic, so put traps out unset for several nights, maybe while you are getting camera placement tuned, and then add bait but not set for a few nights. Then, when you seal the holes, bait and set the traps. You will start trapping almost immediately…good idea to have gloves, masks, grocery store (aka body) bags, and new bait. I used peanut butter and attractant and some cheetos.
-7) Really good idea to replace ALL trim and siding where it touches the roof line with cement fiber (aka Hardie) board. In my case, I seal up holes, and in their desperation to get out they just moved down a few feet and chewed a new one out of the regular siding.
-8) I have some supplies (traps, attractant, I think), some wire mesh if you want/need.
-9) Once you’ve taken care of all entry points and confirmed no more activity in attic, i.e. they are no longer getting in, you can start poison baiting around the house exterior. I prefer the yellow kind (“just one bite”). Don’t buy in bulk…as it is an organic compound, it has relatively short shelf life.
-10) While you are using cameras to figure out their activity and movement patterns, you can usually figure out where on the outside they are getting up to and into your house. In my case it was along my fence rails (rat droppings were obvious once I knew where to look). That was where I put bait pieces so they would have to walk right over them. You’ll need to put out plenty 2 nights running once a month on an ongoing basis, I bet. But, in practice, put bait out each night until it stop disappearing, wait a month or two, repeat.
-11) But, again, this is a slog if the problem is as significant as you’ve described.
