Like many people who breed birds in aviaries, we have an ongoing problem with mice. They dig tunnels under the aviaries and come up inside to feed on the spilt seed and husks and whatever else is there. They won't harm the birds physically, but they leave their droppings, which pollute the floor for the birds which sometimes leave their perches to feed on the ground/floor of the aviary. In some cases, people concrete the entire floor of their aviaries, but we aren't in a position to do that, so the structure is mounted on concrete pavers which are all around it, so foxes and rats can't get inside, but the mice can and do.
Some people set poison baits to kill the mice, but the chances are a bird might pick it up as well. Or if the mice live long enough to go back into their tunnels and outside into the yard, predators would pick them up and die from eating the poisoned mice. So we set a particular type of trap which entices the mouse inside, but they can't get out again. I use mostly peanut butter to entice them, but sometimes use cheese. When we find the mice in the traps (there could be just one, but most times there are several, up to 8 at one time!), we take the trap out into the yard and decide what to do with the mice. My husband used to immerse the whole trap in a bucket of boiling water, but when he told me about this, I begged him not to do that any more, as I said you could hear them squealing. He said he didn't, but I didn't want to know about it, so now he leaves it up to me to dispose of them.
We have kookaburras visit us from time to time, and they must keep an eye on our yard from vantage points, as whenever there is a mouse in a trap, there will be one or more kookaburras waiting on the fence for me to bring the trap out . When I do, I put it on a garden table nearby, and the birds swoop down to inspect the mice. As soon as I open the trap, the kookaburras swoop, and the mice are gone. Ken says this is cruel, but it is a lot quicker than boiling them alive, and after all it is nature's way for the kookaburras to keep the vermin population under control. On the occasions when they aren't around, I just let the cats out of the house, and set the mice free for them to play with. Now that really upsets Ken as he says the cats torment the mice before eating them, and that is cruel too!
So here are some of our feathered friends waiting for their hot meal: