 Some philosophers have proposed that ‘Apis mellifera’ rigidly designates an abstract object, a kind or property. One might say that ‘Apis mellifera’ designates the honeybee kind in every possible world: it never designates any other kind, like the bumblebee kind, say. That might be said to make the term rigid. Something similar could be said for ‘water’, ‘heat’, and ‘redness’. But a number of objections have been issued.