CW animal death
This is an unpleasant subject for many, but if you're facing rodent invasion like we have here a number of times in the last few years, there isn't a lot of good information out there.
First of all, if your visitors number in the thousands or tens of thousands, your only solution is bucket traps or in the case of rats, barrel traps. Take an oil drum, fill it halfway with water, fasten a wooden plank so it swings freely on a spring or rubber band to reset - and put some peanut butter on the end. The rats walk the plank, it swings, they drown. It resets. These will hold a few hundred rats before you need to clean them out (every 2 or 3 days for a large invasion). It is not a pleasant outcome for anybody involved (especially the rat), but this is a last resort when you wake up to critters chewing through your ceiling above your head and just need it to stop.
The standard procedure is poison. We've moved away from poison because of secondary effects. The animal wanders into a field and dies, and a bird (like a wedge-tail eagle) or other critter comes along and eats it. These animals die also. Not a good solution if you're in a wildlife corridor; as we are.
There are some new formulations which don't have secondary effects. These are called eco-poisons or something like that. They work by dehydration. if there is any water around, they are useless. But they won't kill a secondary animal that eats the carcass.
Anyway, for smaller invasions and one-off use, I've found this:https://housetradesupplies.com.au/ratsak-y27-1058-electronic-rat-trap-no-touch-disposal-removable-kill-chamber-y27-1058.html
They're a bit pricey but worth it. Takes four C cells and a dab of peanut butter. The critter enters the chamber and gets hit with a massive thunderbolt and dies instantly. Dump it the next day - anywhere; without worrying about secondary effects. I just drop them in the paddock and birds feast on them with no ill effects.
Anyway 5 out of 5 stars if you've got a dirty job to do and are looking for the right tool for the job.