Ticks

The growing global battle against blood-sucking ticks
Scientists have no shortage of ideas about how to stop tick-borne illnesses. What is holding them back?
Melinda Wenner Moyer
25 August 2015
http://www.nature.com/news/the-growing-global-battle-against-blood-sucking-ticks-1.18227

Ticks then thrive on the rodents, which are poor groomers.
Studies suggest that larval ticks have a 50% chance of surviving when they feed on mice, but only a 3.5% chance on opossums.