I've been coming here since I was an undergrad at UNLV in 2002. Back then there was a bigger emphasis on natural history. I recall that there was no less than three stuffed bears, including a polar bear, and a lot of stuffed birds. They also used to have live animals out front, but do not any longer.
Now the emphasis seems to be shifting towards rotating art displays, which suits me. My favorite recent exhibit was the Ice Next Time," an exhibition of fictional post-apocalypse textiles, clothing, and artifacts.
There is an alcove with relevant documentaries and videos playing that you can enjoy, and the museum often has events for all ages, including fun stuff for both kids and adults.
The xeriscape outside is one of my favorite places on the UNLV campus because it gives you a nice shady place to relax and enjoy desert plants (and lots of birds and lizards).