For TMSS participants. I only made one trip to the tall grass, but managed to pick up a couple deer ticks. They are only slightly larger than a pin head, but dug in and caused swelling. They are a bitch to get out. Doc gave me a dose of doxycycline for the Lyme bacteria. So if you have any red swelling around a very small bite area, dig in and see if you have one of these. They don't scratch out, so get the tweezers.