A bit of information I've been itching to share with you: not all insects are dormant around here during the winter months.  Take a close look at the snow in your yard, if you see what looks like spilled black pepper, look more closely.  If those "pepper flakes" are moving, it's probably "snow fleas."

The "snow flea" isn't really a flea at all, but an insect called a springtail.  They're harmless creatures with a natural anti-freeze that allows them to remain active in cold conditions.

Details from Iowa State Extension & Outreach here: ISUExtensioSnowFleas.