^ I watched that this weekend too! These guys make some consistently darn good videos. Good balance of slick production, entertaining, and informative.
They're north of the Copperhead's range in PA, so I wouldn't necessarily expect one up there. But that general area has a dense population of Rattlers. They can become very locally abundant in spots, as was evident here.
For anyone watching, one small piece of constructive criticism of what you see in this video...I know it was early season yet (mid-May), but I'd recommend wearing at least long pants for that kind of excursion. Mainly from a tick perspective, but also Rattlers. (I also wear knee high snake gaiters up in that area.) I was nervous watching them walk through the young undergrowth in just shorts, and crocs at some points. (See the title shot on the link afish posted for what I mean.) By now, those ferns are much taller and you can't always 100% see where you're putting your feet. My experience with Rattlers is they don't all rattle at you (most I've encountered haven't actually), and in some cases I was within one step and striking distance before I saw them. They still didn't move or get defensive, and I think you'd actually have to step on it to get bit, but I think this underscores the value of gaiters.
Maybe the Rattler encounters (especially the night one) will lead them to the same conclusion I came to regarding wearing gaiters up there! Sounds like they learned a good bit from the outro to the video. Good stuff.
Link to the gaiters I have:
Snake Gaiters
Enough adjustability to go over both pants alone, and waders. Mine are about 10 years old and I'm sure I have hundreds or even thousands of miles walked in them. For $50, they're one of the best value purchases I've ever made in terms of FFing gear. I wear them any time I'm north or west of Blue Mountain, or in Michaux SF. Though honestly, I should just wear them 100% of the time as if nothing else, they're very good at protecting your lower waders from thorns and stick punctures.