Humans are continually creating new expressions and novel utterances by manipulating their linguistic resources to describe new objects and situations. This property is described as productivity (or “creativity” or “open-endedness”) and essentially means that the potential number of utterances in any human language is infinite. The communication systems of other creatures are not like that. Cicadas have four signals to choose from and vervet monkeys have thirty-six vocal calls. Nor does it seem possible for creatures to produce new signals to communicate novel experiences or events. The honeybee, normally able to communicate the location of a nectar source to other bees, will fail to do so if the location is really “new.” In one experiment, a hive of bees was placed at the foot of a radio tower and a food source placed at the top. Ten bees were taken to the top, given a taste of the delicious food, and sent off to tell the rest of the hive about their find. The message was conveyed via a bee dance and the whole gang buzzed off to get the free food. They flew around in all directions, but couldn’t locate the food. (It’s probably one way to make bees really mad.) The problem seems to be that bee communication has a fixed set of signals for communicating location and they all relate to horizontal distance. The bee cannot manipulate its communication system to create a “new” message indicating vertical distance. According to Karl von Frisch, who conducted the experiment, “the bees have no word for up in their language” and they can’t invent one. This limiting feature of animal communication is described in terms of fixed reference. Each signal in the system is fixed as relating to a particular object or occasion. Among the vervet monkey’s repertoire, there is one danger signal CHUTTER, which is used when a snake is around, and another RRAUP, used when an eagle is spotted nearby. These signals are fixed in terms of their reference and cannot be manipulated. What might count as evidence of productivity in the monkey’s communication system would be an utterance of something like CHUTT-RRAUP when a flying creature that looked like a snake came by. Despite a lot of research involving snakes suddenly appearing in the air above them (among other unusual and terrifying experiences), the vervet monkeys didn’t produce a new danger signal. The human, given similar circumstances, is quite capable of creating a “new” signal, after initial surprise perhaps, by saying something never said before, as in Hey! Watch out for that flying snake!