Perhaps you want your insect to be very still so you can paint codes onto it or so that you can make it magnetic. Maybe you want to reduce the injury to your cockroach during very delicate cyborg surgery.
Whatever the reason, here's a way to get a device that's
- inexpensive ($30)
- Fast acting (some insects fall asleep in a second or two)
- Safer than some methods (some other successful methods include dipping your insect in ice water, or putting in the freezer, but I have had less luck not accidentally killing them with those ways).
In short, it's just a small paintball C02 can modified with a on-off- valve.
For the purposes of demonstrating how docile you can make your subjects, I will also show in this instructable how to graffiti tag a bee.
Step 1: Go to Friendly Paintball Shop
From the previous instructable http://www.instructables.com/id/Paint-Ants-for-Science/, jgencinc (http://www.instructables.com/member/jgencinc/ ) suggested finding a paintball shop.
In the Atlanta area there is a great one called Classic Paintball with super friendly people. Simply describe the problem to your paintball people, and if they are good, they will know that they need to remove the normal paintball valve, and install a hand-turnable one. This involves lots of twisting, sealant, and torches. They were nice and did it all for me! You will also need a little hose to attach to the tank. My total was 31 dollars for all of it!
Bring some sample insects to test out, (the paintball people might want to see their new device in action!) and make sure to dunk your new tank underwater to check for leaks.