Humane Way of killing Mice

I've also had good luck using canned air. I use the Fellowes brand found at WalMart. Put the mice in a ziplock or other airtight container, fill container with a good bit of the canned air, and within about 10 seconds their breathing slows, and within about 1-2 minutes, they are gone. It has a sedative effect and I haven't witnessed any struggling.

We have used this at home to put ailing rats and mice to sleep, and they just calmly pass away. You may want to try this if you don't have good access to CO2 or dry ice.

Alright thanks.

You can build up your own CO2 gas chamber, with pvc and the CO2 bottles used for paintball with a hose. Its probably the most humane way to kill them, plus, a CO2 bottle can last for months or so Im told.