What happens to a tick that has drunk blood? - briefly
The engorged tick swells dramatically as its abdomen expands and digestive enzymes convert the blood into nutrients for egg development. It then remains inactive while it digests the meal and prepares for molting or reproduction.
What happens to a tick that has drunk blood? - in detail
After a female tick completes a blood meal, the ingested fluid triggers a cascade of physiological changes. The abdomen expands dramatically, sometimes increasing its volume by tenfold, to accommodate the volume of blood, which can represent up to 200 mg in a single feeding. Stretch receptors in the cuticle detect this expansion and signal the nervous system to halt further attachment attempts.
Digestive enzymes, primarily proteases and lipases, are secreted into the midgut lumen. These enzymes break down proteins, lipids, and carbohydrates into amino acids, fatty acids, and simple sugars. The resulting nutrients are absorbed across the gut epithelium and directed to the fat body, a storage tissue analogous to the liver in vertebrates. The fat body stores excess nutrients as triglycerides and glycogen, providing energy for the next developmental stage.
Hormonal regulation shifts dramatically. The rise in hemolymph volume stimulates the production of ecdysteroids, which initiate molting. In hard‑tick species, the engorged nymph or adult molts within a few days, shedding its old exoskeleton and emerging with a new, larger cuticle. Soft‑tick species may remain attached for weeks, repeatedly feeding and enlarging without molting.
Reproduction is activated. In many species, the blood meal supplies the resources needed for oogenesis. Oocytes develop within the ovaries, mature, and are released into the hemocoel. After a short interval, the tick deposits eggs in the environment, often laying several hundred to several thousand depending on species and meal size. Egg production consumes a substantial portion of the stored nutrients.
During the post‑feeding period, the tick also undergoes immune modulation. Antimicrobial peptides are up‑regulated to protect the gut from pathogens introduced with the blood. Any pathogens the tick acquired while feeding—such as Borrelia, Rickettsia, or viruses—may be translocated to the salivary glands, preparing the insect for transmission during its next attachment.
Finally, the tick detaches from the host. The attachment cement, a proteinaceous secretion, is enzymatically degraded, allowing the tick to release its mouthparts. The tick then seeks a sheltered microhabitat to complete digestion, molting, and reproduction before resuming its quest for the next host.