I don't think that there is "stuff" as such now that sheep dip is no longer used . They are getting worse because of that , a gamekeeper on the Wyvis may have died due to Lyme's . Being covered up is the best bet , keep out of bracken if possible . Inspect , use tweezers if you have them . when you get home inspect clothing and give clothes and good airing don't bring them in until your're sure they are clear .Camping is worst as you are less likely to get a good inspection until a return to home and you are sleeping close to clothes that may have them attached . It might seem a bit OT but could prove worth the trouble .