Fleas...Is Bubonic Plague in our Future?

Hi Steve I just had something happen here I have never seen before. (see photos below) We had a very intense snow storm which lasted about 2 hours come through here, about 2 hours ago which left about 3 inches of snow. I decide to go out and clean off the deck and sidewalk a few minutes ago. Just as was starting to clean the snow off the sidewalk I noticed very small black specks all over the snow. I looked closer and notice the specks were Flea's. I started looking around me and noticed there were flea's everywhere. Thousands and thousands of flea's. I took a few pictures that I have attached. Have you ever hear of something like this happen after a snow storm. As the storm was occurring I heard several jet aircraft fly over. We are in Craig Montana and very seldom hear jet aircraft flying overhead during a snow storm or for that matter at anytime. There is a low altitude airway that comes over the house with an MEA (minimum enroute altitude) of 13,000 feet. So if I could hear the aircraft, (atleast 3) they more than likely were on the airway and the fact that I heard the aircraft within 10 minutes of each other means something was going on. What do you think? John / Craig Montana