Europe’s Lyme Disease Tick Is More Active at Night, New Study Finds

Ticks are often associated with daytime walks through grass, woodland and countryside. However, new research suggests that one of Europe’s most important disease-carrying ticks may be particularly active after dark.

The sheep tick, scientifically known as Ixodes ricinus, is a major carrier of Lyme disease in Europe. A new study examining the behaviour of these ticks in England has found that their host-seeking activity is predominantly nocturnal. The finding could change how people think about tick exposure, particularly during warm weather and outdoor activities in the evening.

What Is the Sheep Tick?

The sheep tick, or Ixodes ricinus, is an arachnid that can transmit several pathogens. It is best known for its role in spreading Lyme disease, a bacterial infection caused by bacteria including Borrelia burgdorferi.

Lyme disease can cause a range of symptoms. These may include an expanding red skin rash, fever, chills, fatigue, headaches and muscle pain. In some cases, the infection can also cause inflammation affecting the nervous system. Children can sometimes develop facial palsy.

The tick itself does not cause these symptoms. Instead, the disease can occur when an infected tick transmits bacteria while feeding.

The sheep tick can also spread other parasites and pathogens associated with conditions including encephalitis and diseases affecting animals.

Ticks May Be Hunting at Night

The new research provides evidence that sheep ticks are not necessarily most active during the daytime.

According to the study, published in the journal Parasites & Vectors, the ticks’ host-seeking behaviour was predominantly nocturnal. The researchers said the findings have important implications for understanding exposure to ticks and the pathogens they carry.

Ticks use a behaviour known as “questing” to find potential hosts.

During questing, a tick climbs onto vegetation and holds on using its back legs. It then extends its front legs, allowing it to attach to a passing animal or person. Once attached, the tick can feed on blood.

This behaviour means that people walking through areas where ticks are present can potentially encounter them without directly seeing them.

How Researchers Studied Tick Activity

Researchers from the universities of Liverpool and Bristol carried out an intensive sampling campaign at Lyme Park in England.

The study covered the period from January through December 2022. Researchers collected tick samples every four hours by dragging long fabric blankets across the ground. They then examined the data to investigate relationships between tick activity and environmental conditions.

Sampling at different times throughout the day and night allowed researchers to build a clearer picture of when ticks were most likely to be actively searching for hosts.

The results showed that host-seeking ticks were most abundant during hours of darkness. The researchers suggested that lower nighttime temperatures could be an important factor influencing this behaviour.

Why Temperature and Humidity Matter

The study also found that tick activity was influenced by moisture and temperature.

During warmer periods, particularly in May in the UK, fewer ticks were caught around midday when temperatures were higher. By contrast, activity increased during darker hours and around dawn.

The researchers concluded that warm weather could create greater exposure to ticks during the night and around dawn.

Humidity also appeared to influence when ticks were active. During cooler and wetter months, tick activity was more evenly distributed throughout the day. During dry nighttime conditions, ticks could retreat into soil or other protected environments.

This behaviour is linked to the biology of ticks. They do not have particularly efficient mechanisms for conserving water, so they periodically need to rehydrate. Leaf litter and soil can provide protection from drying conditions.

As a result, very hot and dry weather can suppress the ticks’ host-seeking behaviour.

What Does This Mean for People?

The findings could be particularly relevant for people who spend time outdoors during the evening.

Camping, hiking, walking and other recreational activities can bring people into environments where ticks are present. The study points out that summer evening activities may increase human exposure because people are often outdoors after sunset when temperatures become more favourable for tick activity.

The researchers suggested that people visiting tick habitats during cool and humid evenings and around dawn could experience increased exposure risk. However, tick bites remain possible at other times of the day.

This does not mean that people should avoid outdoor activities at night. Instead, the research highlights the importance of being aware that tick activity is not necessarily restricted to daylight hours.

Checking clothing and skin after spending time in areas where ticks may occur can help people identify attached ticks. People should also follow appropriate health guidance if they develop symptoms after a tick bite.

Could Climate Change Affect Tick Exposure?

The researchers also highlighted the potential importance of changing climate conditions.

Temperature and humidity influence tick behaviour, so changes in environmental conditions could affect when and where ticks are active. The source study suggests that climate change could alter exposure patterns across Europe as temperature and humidity conditions change.

The researchers said the findings indicate a potential for year-round tick exposure in temperate regions such as the UK, with higher risks potentially occurring at night and around dawn during warmer periods.

More research is needed to determine how widely these findings apply. The researchers hope similar experiments can be repeated at multiple locations and with ticks from different areas.

Key Takeaways About Nighttime Tick Activity

The new findings provide several important points for people who spend time outdoors:

• Sheep ticks are an important vector of Lyme disease in Europe.
• Their host-seeking behaviour appears to be predominantly nocturnal.
• Tick activity can be influenced by temperature and humidity.
• Warm conditions may increase tick exposure risk during the night and around dawn.
• Hot and dry conditions can suppress tick activity.
• Tick activity can occur throughout the year in temperate regions.
• Evening outdoor activities, including camping, may increase opportunities for human exposure.
• More research is needed across different locations to understand how widespread these behavioural patterns are.

Final Thoughts

The discovery that sheep ticks may be more active at night adds an important dimension to our understanding of Lyme disease exposure.

For years, daytime outdoor activity has been a major focus when discussing tick bites. The new research suggests that nighttime and dawn should also be considered, particularly during warm and humid conditions.

The findings do not mean that every nighttime walk will result in tick exposure. Rather, they provide evidence that tick behaviour changes with environmental conditions and that the risk of encountering active ticks may be greater at certain times.

For anyone spending time in areas where ticks are found, awareness remains important. Understanding when ticks are most active can help people take sensible precautions and recognise that the potential risk does not disappear when the sun goes down.

Source: The Independent, published 21 September 2026. The article reports findings from research published in Parasites & Vectors.

Disclaimer: This article is for general informational purposes only. It is not medical advice and should not be used as a substitute for advice from a qualified healthcare professional. If you are concerned about a tick bite, Lyme disease or related symptoms, seek appropriate medical advice.