horseshoe crab

I went outside this morning and realized there were only four horseshoe crabs on my porch (not the usual five.) Having an even number of h.crabs does a man no good! I thought a friend may have taken one as a joke but no one ever comes over here unannounced. Then I found a squirrel running back to take another! I chased him off and wandered how and why a squirrel would steal a 10 inch crab from my porch, maybe for nesting?