The term 'antennae' is used to refer to a variety of structures that are used for sensing and communication. The most common use of the term is to refer to the two long, thin projections on the heads of insects, which they use to sense their environment. Other uses of the term include 'aerials' (7 letters), which are antennae used to receive or transmit radio waves; 'FEELERS' (7 letters), which are antennae used to detect vibrations in the air; 'ears' (4 letters), which are antennae used to detect sound waves; and 'rabbitears' (10 letters), which are antennae used to detect electromagnetic fields.