antenna

Insects, myriapods, and crustaceans all have a pair of thin, protruding sensory organs on their heads called antennae (the plural form of antenna). The term can also refer to a metallic wire or rod that is used for receiving or transmitting radio waves.

Photo Credit

 
"Insect antennae" by Pearson Scott Foresman is licensed under Public Domain.

Published Works
References

 
Merriam-Webster Online
N.d. Antenna. http://www.merriam-webster.com/dictionary/antenna, accessed October 30, 2014.