We might imagine that the experience of being hunted has taught Rainsford his lesson about killing other animals. But the fact that Rainsford sleeps in Zaroff's bed suggests otherwise. Interpret the ending of this story and what it says about Rainsford and humans more generally.

One would like to think that Rainsford has at least gained some empathy for animals from his traumatic experiences, some insight into what it feels like to be hunted. But the evidence from the text would appear to suggest otherwise. We don't know for sure if Rainsford actually kills General Zaroff, but it would appear to be the case, otherwise how else would he wind up sleeping so soundly in his bed? The suggestion here is that Rainsford, having killed Zaroff, has now resumed his previous position as a hunter. He's experienced both sides of the equation; he's been hunter and hunted and, as if he didn't know already, hunter is definitely better.
What all this appears to indicate is that man, despite being a part of nature, at the same time wants to rise above it. He constantly needs to be reminded of his alleged superiority over the the natural world and everything in it, especially animals. Man is simply too proud to empathize fully with the animal kingdom. He somehow feels that doing so will place him on a much lower level of existence.
In the character of Rainsford we see an example of man's seemingly insatiable desire for control over others, whether it's other human beings or animals. And in Rainsford's good night's rest in Zaroff's bed we see the feeling of power and satisfaction that humans derive from domination and control, something that sets them apart from the animals.