I have had had a Kentucky flat millipede for over a month now at 74-75F. The sensitivity appears to vary greatly. He also eats regularly, which is a common issue with the species in captivity.They are very difficult to keep alive in captivity, they are extremely sensitive to temps above 68-70F ito seems, (most localities can't even survive being held in a human hand for long), and may need substrate from where they were collected to breed. No one I know of has been successful getting them to reproduce in captivity, let alone live more than a few months.