In reply to Craig Mc:
I got a tick on my knee last month, I was wearing boots, long socks, long trousers, gaiters, and waterproofs over the top (it was one of those days) and yet the b'stard still got in.
Yet somehow last weekend I only got 3 despite wearing fell shoes, short socks, and shorts, and descending deer tracks through deep heather.
My partner of course got none at all on either occasion.