Springtails or snow fleas can occur on the surface of the snow in groups of a thousand or more. They are extremely small insects only 1 to 2 mm. in length. As you can see from the diagram as well as the SEM photo they are also wingless.
Snow flea on a mcroscope slide. Taken with a "child's" QX3 Camera
The following links will provide you with more information on springtails.
Life
cycle of the springtail
Springtails
can jump
General
background information on springtails.