Keith Thomas, Man and the Natural World
(New York: Pantheon Books, 1983), p. 31 (note omitted):
Even so, there was a marked lack of agreement as to just where man's unique superiority lay. The search for this elusive attribute has been one of the most enduring pursuits of Western philosophers, most of whom have tended to fix on one feature and emphasize it out of all proportion, sometimes to the point of absurdity. Thus man has been described as a laughing animal (Thomas Willis); a tool-making animal (Benjamin Franklin); a religious animal (Edmund Burke); and a cooking animal (James Boswell, anticipating Lévi-Strauss). As the novelist Peacock's Mr Cranium observes, man has at one time or another been defined as a featherless biped, an animal which forms opinions, and an animal which carries a stick.
Bernd Heinrich, Summer World: A Season of Bounty
(New York: Ecco, 2009), p. 186, finds yet more evidence of human uniqueness:
However, even though any one nonhuman mammal species has the dubious honor of hosting only one of each louse or flea species, humans are unique: we have three species of lice. They are head lice (Pediculus humanus capitis); body lice (Pediculus humanus corporis), which live primarily in clothing; and pubic lice (Pthirus pubis).