Ramblers have been warned to be on their guard against a tiny blood-sucking insect after cases of a potentially-fatal disease rose dramatically.
The tick can be found in heather and undergrowth
The Ramblers Association has issued urgent advice to its members telling them to be on the lookout for parasitic ticks.
The tiny insects thrive in moist, coarse vegetation such as the heather prevalent in the Scottish Highlands.
They are normally carried on animals such as sheep, deer and cattle, but can also be transferred to humans walking through undergrowth.
Among the illnesses carried by the ticks is Lyme Disease, a rare ailment which in the most severe cases can attack the central nervous system and the heart.
Rise in cases
And with the traditional grouse-shooting season set to get under way later this month, those taking to the hills have been warned of the dangers they could
An article on ticks and Lyme Disease has been posted on the Ramblers Association's website and says the threat posed "cannot be ignored".
The ticks hook onto the skin and suck blood
"People who walk in the countryside through rough vegetation, especially bracken, are most at risk," the website warns.
Government statistics show that cases of Lyme Disease in Scotland have risen from two in 1992 to 85 last year, although so far no one has died.
The Highlands also has one of the highest rates of the disease in northern Europe, with 16 cases per 100,000 people.
Lyme Disease can remain in the body for many years and can cause long-term problems such as paralysis of the facial muscles and chronic arthritis.
Early signs of the illness include a red blotch over the bite area, flu-like symptoms and aching joints.
Sheep carry ticks
The ticks, which are no bigger than the size if a grape pip, pose the highest risk between April and October.
Walkers have been warned to wear long-sleeved shirts and trousers and to keep their cuffs fastened and their trousers tucked into their socks to avoid being bitten.
Anyone who finds a tick on their body should remove it immediately with tweezers, making sure none of it is left on the skin.
The Game Conservancy Trust has enlisted the help of scientists to look at ways of reducing tick numbers.