How Colors Can Attract the Ancient Gaze of Fleas and Ticks

Colored flea and tick clipart isolated on white background

People have a unique relationship with fleas and ticks. On one hand, most people don’t find fleas and ticks visually appealing. There’s an undeniable beauty to the rainbow of colors visible upon a butterfly’s wings. Meanwhile fleas and ticks tend to just fade into the background. We don’t typically associate fleas and ticks with bright colors. This is in part due to how fleas and ticks use color to relate to the world.

A butterfly uses color to attract other butterflies. Fleas and ticks occupy a very different ecological niche. These species have a parasitic relationship with other organisms. Fleas and ticks do use color to their advantage. However, these blood sucking organisms use color as a tactical advantage against their hosts rather than as a signal to each other.

All of this raises an important question. How do bloodsucking species look at the world? Most conversations about bugs come from a human point of view. We talk about our own subjective take on fleas and ticks. Of course there’s also the issue of how fleas and ticks interact with our pets. But what about the other side of things? How do fleas and ticks see their environment? Do they have color preferences and their own idea of what’s ugly or beautiful? Are fleas and ticks specifically attracted to some colors? Let’s find out.

Silhouette of a flea and a tick

A Surprising Number of Differences Within What Many Assume Are the Same Organism

The first thing to keep in mind is that fleas and ticks are quite different from each other. People often assume that they’re the same species. If not, then people will usually assume that fleas and ticks must be related.

The surprising reality is that fleas and ticks belong to two separate biological classes. Most people are correct with their assumption that fleas are insects. Ticks may share the same food preference as fleas but they’re actually arachnids. In fact, fleas are more closely related to lobsters than to ticks.

All of this is important when trying to understand how fleas and ticks see the world. Humans often view fleas and ticks as very similar to each other. It’s true that both species occupy a similar biological niche. However, fleas and ticks are both an endpoint of a lengthy process of biological divergence.

A Long Lineage and an Equally Ancient Way of Seeing the World

146 million years is a very long time. This is a time period where the tyrannosaurus and triceratops towered over the world. But humanity is all too familiar with one organism which originated during this period. The cretaceous period is the era in which ticks first came into being. And the modern tick hasn’t changed very much from its distant ancestors.

Tick inside a drop of amber

It’s important to keep the age of ticks in mind when looking at their anatomy and color preferences. Ticks are an incredibly successful species. But at the same time they haven’t changed much over the millennia. Ticks are still the product of a world which was primitive in comparison to what’s seen today.

A tick’s view of the world is very different from that of humanity. In fact, this tiny arachnid’s vision is even distinct from that of insects. The key to understanding a tick’s vision can be found in the idea of seeing things in a different light.

A Different Type of Brain for a Very Different Type of Organism

One of the first surprises about a tick’s vision is where it even originates. Most animals, even most insects, have eyes on their heads. An animal which relies on sight needs to reduce the amount of time needed to react to stimuli. Given that an animal’s brain is typically located on its head then it makes sense for the eyes to be there as well. The less distance for optical signals to reach the brain, the faster an organism’s reaction speed.

A tick’s brain is located more centrally within its body. The eyes follow along with that unusual placement as well. This means that a tick essentially looks at the world from midway down the sides of its body. One would be quite correct in assuming this would change how an organism sees the world.

Group of dog ticks isolated on white background

A Tick Sees the World in a Very Different Light

So what can a tick actually see with those very old, very oddly placed, eyes? The simple answer is that it doesn’t see very much at all. This is in large part because a tick doesn’t really care about the look of the world. It’s far more centered around heat and smell. In fact, some species of tick have discarded the entire notion of eyes. The majority of ticks do have eyes though. And in some ways they use those eyes to see what to humans would be a world of shadow.

A tick mostly sees light and the absence of light. A tick will usually see motion as well. This might not seem like much to work with at first. However, one needs to consider how ticks get onto their prey. Ticks generally sit at attention when they’re not on a prey species. A tick will sit poised and ready to latch onto a perfect source of the blood it subsists upon. When a tick looks at the world, it’s trying to pick up on patches of unprotected skin.

The tick will primarily try to sniff out smells which alert it of a living breathing organism nearby. The tick can also feel body heat as living beings come close to it. Finally, ticks with eyes are trying to see that light patch where hair or fur ends and skin begins.

The Trifecta of the Tick’s Worldview

Closeup photo of tick on yellow colored clothes

So far we’ve seen just how strange ticks are. But how does all of this work into a tick’s worldview? A tick is primarily looking for skin. This means that they’re looking for lighter colors. This paints a rather worrisome picture for people looking to get out and enjoy pleasant spring or summer weather.

The clothing people wear in nice weather tends to be exactly what a tick is looking for in a meal. A tick is generally swimming in a constant sea of sensory input. When a person comes near it, the tick will sense someone’s body heat. The tick will also smell the carbon dioxide coming out of a person’s mouth. And finally, the tick will see a person’s skin.

If a tick can be said to love the sight of anything, it would be unprotected skin. However, it’s important to keep in mind that a tick doesn’t rely on vision. It has a very poor ability to really see the world. It can sense a lot of what makes us living beings. But when it looks at us, it’s primarily attracted to skin or anything which looks like skin to it. And for a tick, that means anything which has a fairly light color scheme. Think of the bright whites and yellows often favored during spring and summer. That’s exactly what a tick loves to see.

When we look at a family in bright spring colors, we feel the joy of the season. We see colorful outfits and smiles. A tick smells the carbon dioxide from those smiles. And it often interprets the fun, bright colors as unprotected skin. This tends to make humans an appealing meal for ticks. We look around and see happy people. But a tick sees a trifecta in the look, smell and heat of a human in their spring or summer best. A human wearing whites and yellows looks like a giant mass of unprotected skin to ticks.

Jumping Into the World of Fleas

Dog flea Ctenocephalides canis on white fur. Microscopic photo

We’ve touched on the fact that fleas and ticks are surprisingly different from each other, but just how different are they? To begin, fleas are true insects. This is quite different from the arachnid family line of the tick.

One of the things fleas and ticks do have in common is their age. Fleas aren’t quite as old as ticks. The oldest known example of fleas is about 50 million years younger than the oldest tick. However, those 100 million year old fleas are still quite ancient by any definition of the word.

Ancient Eyes and Similar Limitations

The difference between fleas and ticks can be seen quite easily by looking at their eye placement. A tick has eyes on the upper sides of its body. A flea’s eye placement is much more in line with what people expect. A flea, like most insects, has eyes on either side of its head.

This doesn’t mean that a flea’s eyes are commonplace though. Insects typically have complex compound eyes, which can give them an extraordinary view of the world. For example, we can return to the earlier example of butterflies. Butterflies can typically see far more colors than humans. They can even see ultraviolet and polarized light. One species of butterfly has fifteen different types of color perceiving photoreceptors. It’s estimated that this gives them more than three times the color range of humans.

Insects can clearly have a huge advantage in color perception over humans. So one might expect fleas to vastly outperform the poor eyesight of the humble tick. However, that’s not really the case. Fleas are only capable of seeing about as much of the world as a tick.

Closeup of flea at 50x magnification

Returning to a World of Shadow and Scent

Like ticks, fleas mostly look out into a world of shadow. A flea’s eyes are exceedingly primitive when compared to that of most insects. When a flea looks out into the world, it’s typically looking for movement. Color matters to a flea. However, motion is more important to a flea than color. The first thing a flea wants to know is whether or not a living being with edible blood is wandering around.

It’s only after verifying movement that a flea will consider the merit of its target. Fleas love red and blue. And while black and yellow aren’t a flea’s favorites, they’re still inclined to move toward it. Fleas do share a similarity with some other insects in their attraction to light. A flea who sees greenish yellow light will be drawn to it in a similar way as a moth to flame. The main difference between a moth and flea’s reaction is the level of interest. A moth is highly attracted to light. A flea is far more interested in smell or heat than it is light or color.

How Does a Flea React to Summer Fashion

Ticks are generally far more of a problem for humans than fleas. As one might guess, this has something to do with how they see the world. When a tick sees white or yellow, it sees a meal. A flea looking at its favorite colors, red and blue, simply becomes more interested. Color will catch a flea’s attention for a second. However, it won’t be nearly as quick to assume it’s mealtime as a tick would be. Fleas are partial enough to color that it might be best to leave blue or red leashes behind, when taking the family dog out for a walk during the spring and summer months. However, one doesn’t need to worry about color as much with fleas when compared to ticks.

Ginger mongrel dog with open mouth and eyes shut sitting on green grass in a park on a bright sunny summer day with a blue sky

Fleas, Ticks and a Very Different Way of Seeing Our Colorful World

Fleas and ticks are examples of species which see the world in a very different way than humans. They’re alike in focusing far more on their other senses than vision. But when comparing the two, a tick interacts with the world on the basis of vision more than a flea.

Ticks are actively looking for skin to directly latch onto. A flea is aware of color, but it acts in a more scattershot fashion. Ticks reach out toward whites and yellows in the hope of hooking directly onto skin. Fleas haphazardly jump toward anything they find interesting in the hopes of stumbling onto the general area of a meal. Ticks are trying harder to find a single spot to feed on, where a flea is essentially looking for a mobile, living, habitat to graze upon.

One can essentially think of both species as living in a sensory cloud of heat and smell. A flea sees color more as we see the moon on an overcast night. Whereas a tick sees color in a way more analogous to the sun starting to peek out from behind the clouds. Color doesn’t have a tremendous impact on either species, but the tick is a lot more aware of and attracted to color than the flea.