Mice Run In, Mice Run Out

After filling our freezers with venison, our hunter-friends left deer carcasses where scavengers could get to them.  

We expected hawks and crows.

We didn't expect mice! 

The mice puzzle me.  They spend so much time running around.  What is the point of all that energy-expenditure?

What are they up to?

I am reminded of the gross humor of my childhood, as we kids started on the long journey of coming to grips with mortality.  We'd hoot at each other:  You'll be in a grave!    Then we'd all join in, chanting:
The worms crawl in
The worms crawl out
The worms play pinochle
On your snout...
Over sixty years later, I still don't have mortality figured out.  
But these mice seem perfectly willing to play pinochle!
However, they seem that way to me because I have so much to learn about mice.  I asked Mammalogist Drew Ricketts at KSU to help me understand what we see in this clip.  He replied:  

Mice have pretty high metabolisms relative to ours, and they also have small stomachs, so they spend a lot of time zipping from place to place in search of something to eat.  Mice also have to move relatively quickly when they are in the open, so that they can try to avoid becoming a snack for a predator.  A slow, lingering mouse would quickly become a dead mouse.  They also could be grabbing a bite so quickly that it is hard to see in the video.  Animals also tend to check on large resources, because they are important to them.  Finally, carcasses attract predators and would be a dangerous place for a mouse to be.  It is possible that the mice smell evidence of predators that have visited the carcasses, and have a hard time feeling comfortable.

Some mice are very omnivorous, and some mice have very specific diets.  The mice in the video are white-footed mice, and they eat a lot of different things.  They probably don’t spend a lot of time looking for carrion, but, when it is placed in their home range, it is probably a resource that they can’t resist.  

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Thank you, Drew!  Experts who are willing to share their expertise with us lay people are the best!!!  You help open doors that would otherwise remain closed to us.