They work. While many listings feature non-working Critters, the ones that do work are quite rare! All of the Critters I'm selling work! They've been well-maintained, so you can enjoy them for a long time. This series is a fragile toy, so if you find one, buy it! Pocket Critters, released in 1993, were immensely popular. They were always sold in aquariums and zoo gift shops, and there were kids in class who collected them, right? If you're feeling nostalgic, why not start collecting them now? They're in good condition and highly recommended. I've collected everything from the standard ones to those that are hard to find. *I can also check my stock for the Critters you're looking for. (It may take some time.) I also accept repair consultations for your Pocket Critters. Please comment.*