Molecular radar
Certain bacteria can secrete molecules to probe their environment.
This note is currently a stub.
References:
Bray, Wetware (2009), p. 170
[…] Enterococcus faecalis, one of the most troubling sources of infection in hospitals, deploys a secreted molecule like chemical radar. This substance becomes chemically changed if it encounters a target cell, so if the bacterium finds the molecule "coming back" in modified state like a chemical echo, it knows that food must be somewhere nearby.