This stone contains many different inclusions, among them a moving water bubble! This type of inclusion is one of the most fascinating aspects of amber and examples of moving bubbles (gas bubbles trapped in a water bubble) add greatly to the interest and value of a piece. Stones with large moving bubbles clearly visible to the unaided eye are very rare and valuable.

Here we see two of the larger inclusions. There are also meaurements of the one on the left as well as the one on the right. The first one looks like a cranefly, though it is a bit smaller than most craneflies you'll see flying around your porchlight. There are over 300 species of craneflies in North America alone and thousands found world wide. You can well imagine how difficult it is to identify extant species let alone a species in amber which is probably extinct!
The second inclusion is also a member of the dipteran order, perhaps a midge or gnat.