Harpaphe haydeniana / "Cyanide Millipede"

[Xafron]

Because they can secrete cyanide as the name suggests, I was curious if they would be safe to house with the other more typical pet millipede species or if they should be kept alone?

 

[davehuth]

They emit hydrogen cyanide gas when threatened or stressed, so if they're happy and cozy, that reduces the risk. A highly ventilated enclosure might also help. However, I work with numerous cyanide-gassing millipedes, and don't risk it. Although I've never heard of any actual cases of harm occurring in a good enclosure, I've read from experts that it can happen when shipping them together in tight quarters or carrying them in the same poorly ventilated container during field collection. When I collect, I use a container with steep sides and no lid at all.