Looks like sea lice are climbing that ladder too... only this isn't the corporate ladder or social ladder but a ladder to higher up the food web. Actually a new study looked at an interesting question, how is a poor ectoparasite, like parasitic copepods (including the sea lice that often plague salmon farms), supposed to survive if its host gets eaten. It looks like these pesky crustaceans will often jump ship when their hosts are eaten and then infect the predator that ate their former host. At least they're not using some form of brain control to force their initial host to get eaten like so many endoparasites do. The study was published online by the Royal Society's Biology Letters and a summary is available at AAAS.