Soft ticks, Argasidae, are oval or pear-shaped, with mouth parts that are more easily seen from the ventral view. Ixodes, the hard ticks, possess a dorsal plate or scutum, and many of them can transmit Lyme disease to humans.
North American ticks
Argasidae (soft) and Ixodidae (hard)
Updated April 30, 2006
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Soft ticks - Hard Ticks
Photo from Centers for Disease Control and Prevention (CDC)
