Better to Laugh

I am half-way through reading Eat, Pray, Love, and the author brings up the fact that humans are the only species aware that death is in the future.  All other living things do not think about, or even know about, their inevitable deaths.  That got me to thinking…about squirrels, for one.  Is that how they can climb way up in trees, because they haven’t a clue that one false move, one slip on the bark, and they could plummet to their death?  They happily scurry up and down the tree trunk, just content in the moment.  I wonder what it would be like to have no concept of death.