Glue traps are truly awful. Once, when I was a resident, the hospital cleaning staff put some in our residents’ room. One of the other residents was so incensed at this that she brought in one of her pre-killed snake-feeder mice and left it in one of the traps, then called Housekeeping and told them they’d caught the mouse so they could take the traps away. She was one of my favorite colleagues. 
My old house had a bout of mice once when I was younger and my parents put down glue traps. Once I came into my room to find one stuck by the tail, who was startled by my coming in and tried to dart away, only to sproing back and land with a squeak on the trap - on its face 
I didn’t have to deal with diposal, but I also couldn’t argue about the traps at that point, so I just prayed the mice would leave quickly and spare themselves the flushings…
Insects outside of my house I won’t kill, since I can always just leave. In my house, Ill try to put anything crawly outside, but earwigs, roaches and silverfish will immediately get squooshed if they ever show up, sorry.