Adult fleas don’t have teeth. Instead, they have needle-like mouths for piercing skin and sucking blood. Flea larvae, on the other hand, do possess mandibles and mandibular teeth.
How Adult Fleas Pierce Skin
Cat fleas are vessel feeders, as opposed to pool feeders. Capillary feeding is the more efficient method, because the host’s blood pressure gets exploited by the parasite. This results in a rapid feeding process.
Adult fleas don’t have mandibles or teeth. Instead, they possess piercing and sucking mouth-parts. The main feeding structure is called a fascicle which is composed of three needle-like stylets. The outer two are called maxillary lacinae. They are sharp with serrated teeth, like a knife, and are used to pierce a host’s skin. Each lacinia has three rows of teeth that project backwards, reminiscent of shark teeth. The middle stylet, called the median epipharynx, gets inserted into the blood vessel to draw the blood. The epipharynx is armed with 16 teeth, arranged in two bilaterally symmetrical sets. Strong muscles around the mouth aid in sucking.
Larvae Have Mandibles
Flea larvae have powerful mandibles and mandibular teeth which are well-adapted for biting and chewing. These mouth-parts enable the larvae to be free-living, as they can nibble on solid food sources. The larvae aren’t parasitic. They don’t live on a host or suck a host’s blood.