Depends. I have snap traps for the mice, and regularly kill them. We are very close to farmland, the wool store is just up the road, and my next door neighbour is a manufacturer of dried fruit, so he has huge compost bays for all the cores, peels and other detritus. Hence rodents. We also have my surviving old cat Agatha, who was twenty in September, the neighbour’s much younger cats, and several owls who live near us, including one large old female barn owl whose regular perch is on our tv antenna, from which vantage point she regularly targets the mice in Tim’s compost bays. There are also a pair of kestrels who regularly hunt rodents in our yards. There used to be a beautiful big female brown snake who lived in an old disused drain under my big rose tree, but we lost her a few years ago when she was washed out of her lair in winter floods, and drowned. I cried for her, when I found her where she had been washed halfway down the yard. There are younger smaller snakes around now, and I just hope they don’t want to come into the house. I have killed snakes, mostly when they were being a danger to me or the kids, but I would much prefer not to - they are useful animals, beautiful and part of the ecology.