I think our new-ish neighbours have either 2 or 3 cats(not certain if all theirs but theres 3 outside most of the time.I say most as they seem to be out in all weathers, at all times and 1 is quite young- weve been here since october and neighbour was moved in in september (new build houses) so i'd say youngest about maybe 9/10months old now? But it was small at first, started to grow & fill out more as ive started to leave out my pampered puss's leftovers- (he wont go back to it later if he's had only a bit) and its all premium cat food he refuses cheap stuff! So next door cats are all eating good nosh- i also leave water out in a container as my cat likes to drink outside if we take him out(hes 17 now so since moving he only goes out for a bit & back in.) He used to be out whenever he wanted (within reason) but i never left him out at night, or in bad weather, or when we went away- had a nice older couple visit to feed him etc who did that to supplement their income and they loved cats- didnt charge extortionately though.But these cats in neighbourhood now are out all the time, and the young one even sneaked in other week when patio door had blown open, out of colder weather, she had gone to sleep on my best dining chair- i put her back out as she hisses at my poor old boy, so i felt a bit guilty- but i was annoyed at her owner- why doesnt SHE feel guilty?? The 3 cats have taken to sleeping on top of my outdoor storage cupboards now we've had a bit of sun.But thing is, when its proper summer if i leave patio door or any windows open they'll be traipsing in i suppose?