there are a lot of deer that venture onto the runways in the northeast states at night, mainly for the deer to get away from the bugs, There have been several jet accidents because of deer some on Bedford airport and others. I have flown into many of these airports at night to see deer just standing on taxiways/runways while you are landing. There are many laws/rules that some airport have to keep the fencing low enough for deer to be able to migrate through the airport areas...big debate with pilots & environmentalist.
I could see the same up at Bedford as it is surrounded by woods etc and as you drive through the near by towns they are very wooded = lots of deer.