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How Long Does a Tick Feed? And When Does It Get Risky?

TickSpot Guide · August 2026

In short: A tick doesn't feed for minutes but for several days — two to eight days, depending on its life stage. After that it lets go on its own. That's exactly why a quick check pays off: according to the Robert Koch Institute (RKI, Germany's national disease-control agency), the risk of Borrelia transmission rises after an attachment time of more than 12 hours — removing the tick earlier lowers it considerably.

Feeding duration by life stage

The Robert Koch Institute (RKI) gives the following times for the castor bean tick / common sheep tick (Ixodes ricinus):

Other specialist sources give partly longer ranges — for adult females around 6 to 12 days, in exceptional cases up to three weeks. But the order of magnitude is the same everywhere: days, not hours. What that means in practice: a tick you discover may already have been sitting there longer than you realise — and it grows visibly during that time.

Does a tick drop off on its own?

Yes. Once the blood meal is complete, the tick detaches by itself and drops off to moult or lay eggs. Waiting for that is not an option, though: it is precisely during this time that the transmission risk rises. The RKI's recommendation is unambiguous — after spending time outdoors, check your body and remove any ticks you find immediately.

Why attachment time matters for the infection risk

The reason lies inside the tick's body: Borrelia bacteria sit in the gut of an unfed tick. Only when it starts to feed do the pathogens migrate into the salivary glands — and only from there can they be transmitted. That migration takes time. The RKI puts it this way: the tick must have fed for "at least several hours" for Borrelia to be transmitted, and it puts the rise in risk at an attachment time of more than 12 hours.

An important qualification — there is no safe window: The figure of "24 hours" often circulates in advice articles as a threshold. That number does not appear that way in RKI material. And a 2015 scientific review concludes that in animal models transmission occurred in as little as under 16 hours, and that a minimum attachment time could never be reliably established. The only dependable rule is therefore not "within X hours you're safe", but: the shorter the tick feeds, the lower the risk — so remove it immediately.

With TBE it's different — there every minute counts

For the TBE (tick-borne encephalitis) virus, the timing logic of Lyme disease does not apply. The virus does not sit in the gut but is already in the tick's salivary glands, and according to current knowledge it can therefore be transmitted within minutes to a few hours after the bite. Fast removal helps less here than it does with Borrelia — but TBE is far rarer overall, and in risk areas there is a vaccine. More on that in "Tick-Borne Disease Case Numbers in Germany".

How high is the risk in the first place?

To put it in perspective, the RKI gives concrete figures for Germany and Switzerland: after a tick bite, 2.6 to 5.6 percent of those affected develop antibodies against Borrelia, but only 0.3 to 1.4 percent actually develop a recognisable illness. The vast majority of tick bites therefore have no consequences — which makes finding one less dramatic, but doesn't make prompt removal any less sensible. How many ticks carry pathogens at all is covered in "How Many Ticks Actually Carry Disease?".

What to take away from this

  1. Check after every outing in the green — not the next day. The hours you gain are exactly the ones that matter.
  2. Remove any tick you find immediately, not "later" — the instructions are here: How to remove a tick properly.
  3. Don't panic if it had already been attached for a while. Even then, illness remains the exception. Mark the bite site, note the date and keep an eye on it over the following weeks — see "Tick bite — what to do now".

Every hour counts: The tick check with TickSpot takes less than two minutes — free, no sign-up.

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Sources

Important: This article provides general information and does not replace medical advice. If you have symptoms, skin changes, or any doubts after a tick bite, please seek medical advice.

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