I use the term 'tree rat', due to the possible mis-interpretation of calling them 'squirrels' (and all the arguments that can bring on) - don't get me wrong, I like nothing better than watching nature & have spent hours watching rabbits, hares, deer and all manner of birds, from wrens to eagles, I'm not a town dweller, so don't view nature as 'pretty, pretty' and know that it is vicious, I wont use poison to kill a rat, nor a lethal trap, both of those options aren't 'specific' enough (poison will enter the food chain & it's a horrible, painful death) lethal traps will kill/maim anything that sets them off, from mice and voles through to larger animals - so I use either a 'live capture' trap or an air rifle at ranges where I'm usually very unlikely to miss. There is no 'right' or 'wrong' view on the killing of pests - either you agree with it, or you don't - obviously, you don't agree with it, your privilege.