This is a male Ixodes ricinus tick (smaller) shown copulating with a female tick (larger). I. ricinus, the "castor bean" tick, so called because of its resemblance to the castor bean, is a vector for the B. burgdorferi spirochete, the cause of Lyme disease, and is commonly found on farm animals, and deer who are the natural host.
By WHO [Public domain], via Wikimedia Commons
