Transcript:

Today on Animal Fact Files we’re talking about ticks. We’ve probably all heard of ticks. Most of us think of little bugs attached to a pet’s ear or other unfortunate place. I myself always recall to mind the time I was sitting in a restaurant with my family only to discover our trek prior to that had landed us in what we could only assume was a newly hatched nest and our legs crawled with literally hundreds of tiny ticks. After researching this episode, I can only come to the conclusion that we managed across of a large group of seed ticks, which is the name given to the larval form of ticks - but I feel like I’m getting ahead of myself here.

There are nearly 1,000 named species of ticks covering our planet. They are found worldwide, though they’re most populous in the tropics. And when I say worldwide, I mean worldwide. There are even ticks that live in Antarctica. Their hosts are penguins. There are two main types of ticks and then one random type that has a scientific name that reminds me of a chocolaty hazelnut spread. Scientists don’t know how to classify this one because they’re so rare there isn’t enough material to confirm their DNA. So that’s about all we’ll have to say about them. Hard ticks are the ticks with which people are most likely familiar. These ticks have a “shield”, visible mouthparts through all their life stages, and their pedipalps (or those grippy things near their mouths) are club shaped. Soft ticks don’t have a shield, don’t always have visible mouthparts, and their pedipalps look like actual legs. There are other differences, too, but we’ll talk more about those as we go on.

The factor that binds all the tick species together is the fact that they all eat blood. Ticks get their blood meals from a “host”. The host is another animal and can include mammals, birds, reptiles, and even amphibians. Hard ticks typically need two or three hosts to complete their life cycles while soft ticks often need up to six. Some ticks will also feed off humans. This can be a concern because ticks act as vectors for diseases, in fact, they’re often ranked number one or alongside mosquitoes as worst blood feeding arthropods that transmit diseases to humans. A tick can transmit a disease by biting a person after they’ve acquired the bacteria that causes that disease from another animal, likely another host. Take lyme disease as an example. Let’s say a tick crawls up on a mouse and gets itself a full meal of mouse blood. Let’s also say that mouse had lyme disease which is caused by exposure to a certain bacteria. When the tick bites the mouse, that bacteria makes its way into the tick’s system where it’ll set up shop in the tick’s saliva glands. When the tick bites into its next meal, let’s say a human, that bacteria may be transferred through the tick’s saliva, into the tick bite, into the human’s bloodstream, thus giving the bacteria the opportunity to develop in the human. Both hard and soft ticks can be vectors of diseases.

When ticks aren’t causing potential mayhem to the systems of their hosts, they’re likely living on the ground looking for another host. Most ticks change hosts throughout their life stages. The life stages for ticks include the egg, larval, nymph, and adult stages. Soft ticks usually live longer than hard ticks who die shortly after mating or laying their eggs. Soft ticks usually lay several small batches of up to 100 eggs, while hard ticks lay a single batch of thousands of eggs - more than 20,000 eggs were recorded from one clutch! In soft ticks, the nymphs go through instars, or molts, but this does not occur in hard ticks; and soft ticks often feed off their hosts for multiple half hour periods of time while hard ticks will attach and remain attached for days to weeks. When this happens, female hard ticks become engorged making them ten times bigger than their normal size. When they aren’t engorged, ticks usually aren’t more than 3mm long.

Tick eggs are usually laid on the ground and if a larval tick is unable to find a host it will perish, though some ticks have been known to go months without eating. Sometimes they’re also eaten by other arthropods, birds, reptiles, and small mammals - though this can happen accidentally by biting at an area where a tick is attached.

For more facts on ticks, check out the links in the description. Thank you to JaKoby LeVan. Give a thumbs up if you learned something new today, and thank you for watching Animal Fact Files.