Reptiles are few in number in our northern climes. Their inability to generate heat is both their foible and forte. Not having to continuously stoke the internal fire as we mammals have to, all of what they eat can go to powering their muscles or building their bodies. But not having an internal heat source they are relegated to moving about just when the external temperatures allow for it.
I spend an inordinate amount of time observing and advocating for these misunderstood belly crawlers.