10 for 20$ they can be used in bioactive terrariums for your reptiles or as a fun unique pet they are easy to care for. Milkback leavis are much like the dairy cow isopods and are great tank cleaners for more of a harder bodied reptile such as snakes and lizards that don't have soft scales like crested geckos and soft skin like amphibians as they have been repodedley seen chewing on these softer bodied animals. But some people do have success and have not had any issues with this happening and is more than likely due to keeping their appetite in check with plenty of decaying material in the substrate and leaf litter and other supplements for isopods. They are quick to breed as well and may over populate and you may have to remove some as needed or they will be population controlled by your reptile if they eat insects.