Questions for ‘Some ecologists value parasites — and now want a plan to save them’

The human head louse shown here is an ectoparasite, which means it lives on the outside of its host.
Gilles San Martin/Flickr(CC BY-SA 2.0)
The human head louse shown here is an ectoparasite, which means it lives on the outside of its host.
Gilles San Martin/Flickr(CC BY-SA 2.0)