I who am entirely unqualified to do so had today to make an ijtihad. Fortunately, it was only for myself.
A mousetrap yielded up results, but because we are modern politically correct people, the result was alive. It is that kind of mousetrap. Something stirred in my memory about conduct towards rodents and vermin in general, and I thought it to lie in the noble hadith collections, but decided to seek it from the fuqaha of the school, in this case Ibn Juzayy al-Kalbi. He was quite clear that they are to be killed. Rats, mad dogs, wasps etc.
However, it occurred to me that perhaps the judgment from within a civic order, cities, might be different than my case in the countryside with few houses around me, so I cycled a kilometre or so and let the slightly bewildered mouse out in the autumn leaves near a copse of trees. After all, the appalling destruction of life, birds, insects and species in general is unparalleled in the history of the world. Perhaps if it might be necessary to expel mice from the house for reasons of hygiene, there might be no harm in them scurrying about among the trees.
Although it had spent the entire night in the trap, it had not even touched the cheese that had lured it in.