Despite having such striking colors associated with joy and merriment, this showy snail is actually sick, manipulated, parasitized. It is a zombie.
The colors are caused by Leucochloridium paradoxum , a parasite that uses these mollusks as a host to lead them to their true objective: the birds . The snails are only their transport to reach the treetops and attract the attention of thrushes and blackbirds, in whose rectum they will put larvae that will be expelled in their feces to re-infect other snails. And so ad infinitum .
The following National Geographic video explains the process in more detail.
The snail, under the control of L. paradoxum , commits suicide and ends up dying from pecks (although they can sometimes survive and regain certain capacities). The parasite, on the other hand, accommodates itself in its new home, in the intestines of the bird .
L. paradoxum is found in humid areas such as the forests of North America and Europe where its definitive and intermediate hosts are found such as snails of the genus Succinea and various birds (crows, jays, sparrows, and finches).