I'm with Slappy... clove oil (eugenol) is what I use (available at any drug store.) It is supposedly what vets use to anaesthetise fish and should be painless. About 1-2 ml of clove oil, mixed with just enough vodka to dissolve it, in a couple litres of water; they just kind of keel over and die.
I used to use freezing but I'm not entirely sure how nice it is. If you use freezing I would say the faster the better... a drop into ice cold water might be kinder than cooling them down. Truth is it's hard for humans to know exactly what other species feel or don't feel, we're just guessing based on physiology and behavior.
I used to use freezing but I'm not entirely sure how nice it is. If you use freezing I would say the faster the better... a drop into ice cold water might be kinder than cooling them down. Truth is it's hard for humans to know exactly what other species feel or don't feel, we're just guessing based on physiology and behavior.