Unknown Pest

Checking my apiary sites today I found this nucleus hive (which has a colony bees in) had been attacked by something (within the last week). Fortunately the bees appear okay, for now...
I wonder what could do this? Shrew??

The Benefit to Bees In Sub Zero Temperatures

I am hopeful that this cold spell will be beneficial to our bees. It will help keep pests and diseases at bay (bar the woodpecker!) and the bees will not be so active, therefore will not use so much stored honey! Many people think that sub zero temperatures would the most detrimental but the worst weather for bees is damp weather. The main risk this weather is if the bees use up all the stores that they are clustered on and become isolated from other food stored.