Fall on Martha’s Vineyard: The days grow shorter, the leaves turn — and deer ticks make a comeback.

Ticks are part of the seasonal cycle here. The big ones, called dog ticks or wood ticks, are much in evidence from mid-spring to early summer. They’re big and they’re multitudinous, but they’re not the ones that everybody worries about.

During the summer, Trav and I don’t see many ticks. Summer is a PITA in many ways, but ticks are not one of them.

The deer ticks are back. It’s fall.

This “Caution! Deer Tick Habitat” sign just appeared at the state forest trailhead near the West Tisbury School. Such signs are common on conservation lands, but this one was new.

The media are in a frenzy about Ebola virus. I’m probably hopelessly retro to be thinking about ticks, but I’ve long been fascinated by risk — how we assess it and how we deal with it. In the decade just past, I wrote an essay, “My Terrorist Eye: On Risk, the Unexpected, and the War Against Terror.” It holds up pretty well.

On October 17, the Vineyard Gazette posted the obligatory story about Ebola prep: “Hospital Ready to Respond in Unlikely Event of Ebola.” The very first commenter took the paper to task: “Why in your reporting would you say, ‘ in the unlikely event’? No one knows that! People are here on M.V. after traveling the world. It is that unpredictable factor that makes preparedness all so urgent!”

Pass the word: “Traveling the world” does not put one at risk for Ebola.

Walking in the state forest, or almost anywhere else on off-road Martha’s Vineyard, does put one at risk for tick bites and the various tick-borne diseases. Lyme disease is nowhere near as serious as Ebola virus, true, but the risk is real. I know many, many people who’ve had it. Some of them are dealing with chronic Lyme, a condition that some doctors don’t believe exists. Considering that Lyme was identified almost 40 years ago, the lack of scientific knowledge about Lyme and other tick-related ailments is sobering.

About two months’ worth of ticks, mostly courtesy of Travvy

In the near vacuum created by scientific ignorance and medical skepticism, most of us get by with anecdotal evidence and personal experience. Those of us with pets have learned a lot from our veterinarians.

Mysteries abound. I had Lyme last year, I thought for the first time — but the ELISA test suggested that I’d had it before. Huh? I had no idea. Not only could I have Lyme without feeling sick; I could have Lyme without knowing it and it could go away without being treated. (See “Musing About Lyme” for some reflections on the subject.)

I go into the woods anyway. Every day, usually more than once, I go into the woods. With Travvy. Every month I treat Travvy with Frontline. From time to time I find dead ticks in my bed, where Travvy likes to sleep in cooler weather. When we get back from our walks, the ticks usually aren’t dead yet. I pick them off him with a comb and put them in the tick jar.

If I didn’t have personal experience to balance against it, I might pay more attention to the sign. “Don’t let ONE BITE change your life!” it says. One bite from a critter that is, as the signs and pamphlets like to say, “as small as the period at the end of this sentence.” Being an editor by trade, I have no trouble seeing periods, even though — unlike ticks — they don’t move around and I’ve yet to be bitten by one. It’s easy to get the impression that deer ticks are microscopic, as invisible as germs.

If all I knew was what I read on the warning signs and pamphlets — which are ubiquitous on Martha’s Vineyard — maybe I’d be more careful. I’d stay on the trail, use tick repellent, and put my clothes in the dryer for 20 minutes — if I had a dryer, that is. Maybe I wouldn’t go into the woods at all.

But I do. Every day and then some. Even after having Lyme once and maybe twice. Why? Well, it certainly helps that the news media aren’t spewing out Lyme horror stories 24/7. It helps that, though tick-borne diseases can be serious, chronic, and even fatal, I know plenty of people who’ve had them and most of them eventually get their normal lives back.

In my D.C. days, I walked, biked, and took public transportation all over the place. My suburban friends thought I was brave. I thought they were nuts. When I moved to a new neighborhood, I’d feel off-balance and uneasy — for about a week. After walking around for a few days, I began to sort out which sights, sounds, and smells were “normal” and which were out of the ordinary. The place became part of my psychic map. It felt like home.

For my suburban friends, most — sometimes all — of the sights and sounds came from the newspapers and, especially, from TV.

Which is where most USians are getting most of their information about the Ebola virus. There’s better information out there, but it’s a little harder to find and it takes longer to digest. I have plenty of personal experience with ticks and Lyme disease. I don’t have personal experience with Ebola. I hope I never do. But I have access to the accounts of people with extensive knowledge of Ebola and personal experience as well.

It makes a big difference.