Photos
Header photo:
http://www.mlevinephotos.co.uk/imgstore/img_212_m.jpg
Jaguar allogrooming:
http://cdn2.arkive.org/media/A5/A599E5E3-32D0-46CE-8A9E-A4D24392F80A/Presentation.Large/Pair-of-jaguars-allogrooming.jpg
Monkey allogrooming:
http://img.posterlounge.de/images/wbig/gavriel-jecan-affen-pflegen-einander-200650.jpg
Birds allogrooming:
http://www.photovolcanica.com/PenguinSpecies/YellowEyed/NZ08_1956.jpg
Quiz Pictures:
Photo provided by Kelsey Kallapos
http://www.eunansweeneyphotography.com/wp-content/uploads/2009/08/horses-biting-good.jpg
http://cdn.c.photoshelter.com/img-get/I0000_ugeKN06cdc/s/800/VGR-20120823-5486.jpg
http://www.horsetrue.com/images/bigstockphoto_fight.jpg
image from http://www.art.com/