My daughter is too young to understand that things die. She is always catching some sort of frog or lizard and then putting it in a box to keep "forever" without realizing that the things have to eat. I end up having to sneak out and let the captive escape after she goes to sleep.
If you like to look at bugs or have kids that like to look at things like that ThinkGeek has a new toy that might be perfect for them. The toy is called the Electronic Butterfly in a Jar and it looks very realistic. The butterfly is offered in pink morpho, blue morpho, monarch, and yellow swallowtail varieties.
The only downside is that right now they are all backordered for 1-3 weeks except for the pink morpho. The jar looks real and the butterfly has a thin, clear wire that gives it the juice it needs to flutter around the jar. It looks very realistic and you can only see the wire close-up. This will fool many folks so be ready to have tree hugger types call you mean and have to explain. The strange toy costs $19.99.