The two-headed black rat snake at the Cape Girardeau Conservation Nature Center was active Wednesday, more than a decade after it arrived.

The snake, technically speaking, is two sister snakes conjoined at birth. They are set to celebrate their 17th birthday around September, according to Missouri Department of Conservation (MDC) media specialist Josh Hartwig. The black rat snake is a nonvenomous constrictor-type species.

This particular snake is often referred to in the singular, as one snake, but will remain nameless.

"We don't name critters at the nature center, since we still consider them wild," Hartwig explained.

Of two brains sharing one body, one of the sisters appears "more dominant" than the other to MDC naturalist Alex Holmes.

The two-headed black rat snake explores its cage Wednesday at Cape Girardeau Conservation Nature Center.michael leifer

According to Holmes's observations, the dominant head "seems to drag her sister around."

Holmes added both heads are fed independently, even though the heads share the same stomach.

But two heads, Holmes added, isn't only something that happens to snakes.

"This is the same principle as conjoined twins in humans, when two embryos fail to fully divide," he said.