1. Hermit crabs Current Biology
Mark Briffa, Sophie L. Mowles 
Current Biology 
Volume 18, Issue 4, Pages R144-R146 (February 2008)
DOI: /j.cub
Copyright © 2008 Elsevier Ltd Terms and Conditions

2. Figure 1 A shell fight in Pagurus bernhardus.
The attacker holds the defender's shell so that the two shell apertures are opposed and insets its chelae into the defender's shell. In this position, the attacker performs bouts of shell rapping, while the defender is tightly withdrawn inside the shell.
Current Biology  , R144-R146DOI: ( /j.cub )
Copyright © 2008 Elsevier Ltd Terms and Conditions