The butterfly garden is very nice. Especially the hatching station where you can see molting of several species in real time is fascinating. It's also too small to redeem the whole visit.
The rest of the collection is somewhat comprehensive between the depictions of wildlife and an array of artifacts from around the world. However, it has a very dated feel to it, nothing stands out in comparison to other comparable museums around the country, and we found the descriptions very poor. Most of the artifacts and organisms don't have any tags save a generic statement about the whole display. This was also a big flaw of the otherwise attractive looking exhibit The Streets of Old Milwaukee.