I don't understand the hesitation to kill something like roaches, ants, fleas, ticks, etc.
Spiders I get not wanting to kill them though, because they won't transmit diseases, breed out of control, or get into your food.
Also roaches are nowhere near as bad as mosquitoes or fleas. I've had fleas three times from visiting someone's house that I didn't know was infested and it's HELL to get rid of them, and mosquitoes make you not be able to even go outside for 30 seconds without getting bit 3 times.