Argasid or soft ticks are ticks of the family Argasidae. Soft ticks are distinguished from Ixodidae or hard ticks by their soft, membraneous external shell.
Soft ticks typically live in crevices, coming out to feed on animal blood. Few tick-born diseases are carried by soft ticks, although there are some exceptions, such as relapsing fever, which is carried by the relapsing fever tick.