Great ideas -- thanks!Make the cage from 1/2" or 1/2"x1" material and attach 1/4" or screen wire or cardboard temporarily to the inside bottom 4 or 6". Attach it with wire ties for easy removal.
That will make a nice cage and keep the little buggers from escaping while they are small. When they get bigger, you can remove the screen wire.
Making a cage from hardware cloth can be done easily using the zip type wire ties to attach the various pieces together. It won't work for rodents, since they will chew through them. But it works great for birds. No special tools. Won't rust. Strong enough. Change your mind and you can snip them off and reuse the wire. They are cheap.
John