slightly amused with the image of 'humanely killing rats in a trap' ... does that mean killing them as if they were humans?
I'd say have them killed *naturally* ... hand them out to ferret (or python, or anything of comparable tastes) owners, possibly for a small fee covering operating expenses!
Another method (picked up from a mate working in a biotech lab): which sounds cruel but is quick and probably painless:
grab by tail
swing onto table top with enough force to stun then animal for a few instants
put thumb on neck behind skull
yank tail
This will break the neck and severe the spinal cord. Does require some training, though.
For non-lab rats? You first.
That is assuming you could actually keep hold of it long enough.
"grab by tail"
Have you ever tried to grab a wild rat that is slightly peeved at been stuck in a trap for a few hours. Even with good gloves I wouldn't risk it. These rats are riddled with diseases that you really don't want. The only wild rat I pick up is a dead one.
Dave.
I would not even bother with a pistol get the tattiest old spring .22/.25 rifle so you can poke it thru the bars one handed, that way you don't get sprayed with blood. £50 should see you sorted.
Theoben Taunus .22, Custom Ratty .22, BSA Superstar Mk 1 .25, AA S 400 super lite carbine .177 ,Crosman 2300T, Beretta 92 FS,Weihrauch HW45 Silver Star .177
"He who rides the Tiger can never dismount"