Argas persicus is a species of soft-bodied tick (Argasidae) that is common on chickens and other poultry. They like to hide in the wooden parts of the coops and then crawl onto the birds to feed. They can vector a species of bacteria called Borrelia anserina, which produces avian spirochetosis. Soft-bodied ticks aren't really so soft - they just are called that since they look rather shriveled until they fill themselves up with blood.
The image comes from this site.