[0:00]In our last tick video, we learned that ticks are not insects.
[0:08]They have eight legs, so they're arachnids.
[0:14]Also, deer ticks, the ones that give you Lyme disease are a reddish brown color with a dark shield on their back.
[0:30]And maybe the most interesting fact: after feeding, ticks can swell up to 100 times their original size.
[0:47]But you know, amongst all this tick information, there's one question that we didn't answer.
[0:55]How? How are ticks able to expand like balloons and go from this to this?
[1:09]Hmm, that's interesting.
[1:12]There are a few explanations, but this is the big one.
[1:20]The answer is in their skin.
[1:23]Let's take a look at the surface of an unfed tick under a microscope.
[1:31]Huh, it seems like there are a bunch of ridges on the surface.
[1:40]Here's what it looks like from the side.
[1:45]The top layer of the tick's skin is all scrunched together in a bunch of tight folds or pleats.
[1:58]Hmm. Now let's see what things look like as the tick swells up.
[2:08]Will its skin look any different?
[2:13]Here it is at the beginning.
[2:16]Now let's see halfway through feeding, and now towards the end of feeding.
[2:27]Here's everything side by side.
[2:30]The ridges kind of look like they're widening.
[2:37]Let's take a look from the side.
[2:48]Ah, they're stretching out.
[2:55]So, in a way, the surface of a tick is kind of like a piece of paper that's folded up a bunch of times.
[3:07]And as the tick swells and grows while feeding, those folds stretch way out.
[3:19]And that's how ticks can swell up to 100 times their original size.
[3:25]But that's not all. People often ask, where do I get all of these specimens?
[3:31]Well, I'll show you. Click the join button below to see some exclusive behind-the-scenes tours of the museum collections that I film in.
