“…and today we’re talking about a tiny brain with big thoughts. But more on that later.”
The regal jumping spider has those signature big round eyes that make this arthropod kind of cute… but if you watch them long enough, you might see that there’s thoughts behind those black pearls. Jumping spiders have tiny brains, but why do they seem to do a lot more mental processing than other tiny arachnids? Sometimes even a spider has to think about Life, Death, and Taxonomy.
Description of the Regal Jumping Spider
- Looks like someone crossed a fuzzy tarantula with a wind-up toy and then shrunk it in the wash.
- Covered in dense, velvety hairs that make it look more like a tiny stuffed animal than something your aunt wants to smash with a flip-flop.
- Usually black with brilliant white spots and stripes, though some populations sport orange, gray, or even tan coloring.
- Females are often larger and chunkier, while males tend to show flashy iridescent green or blue mouthparts that practically scream, “Look at me!”
- Possesses eight eyes, but the two enormous forward-facing eyes dominate its face, giving it an almost cartoonishly curious expression.
- Thick, sturdy front legs help it grab prey after launching itself like a caffeinated gymnast.
- Doesn’t build capture webs—its body is built for stalking, pouncing, and showing off.
Measure Up
Welcome to the beloved Measure Up segment. The official listener’s favorite part of the show! The part of the show when we present the animal’s size and dimension in relatable terms through a quiz that’s fun for the whole family. It’s also the part of the show that’s introduced by you when you send in audio of yourself saying, singing, or chittering the words Measure Up into ldtaxonomy at gmail dot com.
Lucas The Spider – All Episodes!
Females: about 12–22 mm body length (0.5–0.9 in)
The “Georgia Peach” is a famous symbol of the U.S. state of Georgia. The state produces over 40 commercial varieties, including clingstone and freestone peaches. True or False – 4 female regal jumping spiders go into a Georgia Peach.
True! The average diameter of a Georgia Peach is 2.5 to 3.5 inches (6.4 to 8.9 cm).
Males: about 6–18 mm body length (0.2–0.7 in)
The average Florida orange weighs about 140 grams. It takes about three to yield 8 ounces of juice. But the famous Honeybell orange can be larger. They are actually a rare hybrid of a Dancy tangerine and a Duncan grapefruit… only grown along the indian river and available for a few weeks in January. True or false – 8 spiders go into the honeybell orange.
False. The average diameter of a Florida orange is 2.6 to 3.3 inches… honeybells are up to 4 inches (10 cm).
Fast Facts about the Regal Jumping Spider
- Range: Found throughout Florida, Georgia, Alabama, Mississippi, and parts of the southeastern United States, as well as the Bahamas and nearby Caribbean islands.
- Habitat: They prefer sunny shrubs, tree trunks, gardens, fences, and even the sides of houses where they can hunt in broad daylight.
- Diet: Tiny insects, flies, mosquitoes, moths, beetles, caterpillars, and even other spiders occasionally make the menu.
- Hunting: Instead of spinning sticky webs, they rely on incredible eyesight to stalk prey before launching jumps up to 50 times their body length. It’s basically Olympic long jump with zero warm-up.
- Vision: Their huge front eyes provide some of the sharpest eyesight of any spider, allowing them to judge distance almost like a tiny cat with eight legs.
- Mating: Males perform elaborate dances by waving colorful front legs and flashing their shimmering chelicerae. It’s equal parts ballroom dancing and desperate job interview.
- Silk: They don’t use webs for hunting, but they always leave behind a silk safety line before jumping—because even tiny daredevils believe in wearing a seatbelt.
- Social Behavior: They’re mostly solitary and would rather avoid each other unless romance—or lunch—is involved.
- Sounds: They don’t chirp or hiss, but they can produce subtle vibrations by drumming or scraping body parts during courtship and territorial displays.
- Predators: Birds, lizards, frogs, praying mantises, larger spiders, and parasitic wasps all consider them bite-sized appetizers.
- Lifespan: Most live around 1-2 years, though females often outlive males after the breeding season.
- Bonus Weirdness: They’re one of the few spiders that many arachnophobes end up liking because they seem oddly curious. They’ll sometimes stop, tilt their heads, and stare back at you like they’re silently judging your life choices.
Major Fact: Tiny Brain, Big Thoughts
Jumping spiders in general, seem to be much smarter than the average arthropod. And one of the biggest surprises is that jumping spiders show smarts with an incredibly small brain—well under a milligram.
Rather than adding more neurons, evolution appears to have produced highly specialized neural circuits that efficiently solve the kinds of problems jumping spiders encounter every day.
How smart are they?
Planned Detours
This 2016 study found they can plan a route to prey before they start moving.
The researchers placed each spider on top of a tower where it could see two possible paths. One winding walkway eventually led to prey, while the other led nowhere. Because the platform was surrounded by water—which these spiders avoid—the only way to reach the prey was to commit to one of the two circuitous paths.
The crucial part of the experiment was that once the spider left the tower, the prey was no longer visible. To succeed, the spider had to remember where the prey had been, select the correct detour in advance, and continue following that plan without seeing its target.
All 15 species chose the correct walkway significantly more often than would be expected by chance. In many cases, the spiders even walked past the incorrect path before reaching the correct one, resisting the temptation to take the first available route.
Recognize Individuals
We’ve talked about spiders that need to be careful approaching mates because females may mistake them for prey…
In 2025, researchers repeatedly introduced regal jumping spiders to the same unfamiliar spider using a transparent barrier that prevented physical or chemical contact, leaving vision as the primary cue. They measured how much attention each spider paid to the other by tracking its position and orientation.
At first, the spiders spent considerable time observing the unfamiliar individual. As they saw the same spider over repeated trials, their interest declined—a classic example of habituation, where an animal stops responding strongly to a familiar stimulus. When the researchers substituted a different individual of the same sex, the spiders’ attention immediately increased again. This “dishabituation” showed that they noticed the change wasn’t just “another spider,” but a different spider.
The team also tested memory by separating encounters by both short and long time intervals. Even after these delays, the spiders still responded differently to familiar versus unfamiliar individuals, indicating they retained a memory of specific spiders rather than simply becoming tired of looking at spiders in general.
Silk Dreams
This 2022 study investigated whether jumping spiders experience something similar to REM (rapid eye movement) sleep… which is a sleep stage that has been associated almost exclusively with birds and mammals.
The researchers filmed resting spiderlings throughout the night using infrared cameras. During otherwise motionless periods, they observed regular bouts of rapid retinal movements along with body twitches, leg curls, and occasional movements of the silk-spinning organs.
These episodes happened at predictable intervals, becoming longer and farther apart as the night progressed—a pattern strikingly similar to REM sleep cycles in humans and many other vertebrates. Between the active periods, the spiders remained still in a quieter resting state.
That could mean jumping spiders enter a REM sleep-like state. But the researchers are careful not to claim that spiders experience dreams or human-like sleep. Instead, they argue that the combination of rhythmic retinal movements and coordinated muscle twitches represents a distinct phase of sleep analogous to REM.
Movable eyes are extremely rare among arthropods…so jumping spiders provided a unique opportunity to observe eye movements that are impossible to see in insects.
One must wonder… why?
Here are some possible reasons:
Advanced vision created a demand for a bigger “mental toolbox.”
Most spiders are ambush predators… waiting in a web or a whole. But jumping spiders use sharp vision to find and hunt down prey.
They can visually detect prey from several body lengths away and have excellent depth perception and color vision. But, visual information is only helpful if you have a brain to process it.
Advanced vision comes with enhanced neural processing for:
- object recognition,
- distance estimation,
- memory,
- attention,
- and decision-making.
Hunting requires planning instead of reflexes
The detour experiment shows jumping spiders plan out paths to reach prey. Perhaps, their style of active hunting requires more decision making.
Again, other active hunting arthropods may follow chemical signals, but jumping spiders are looking for prey.
They hunt dangerous prey.
Jumping spiders are quite small compared to the things they hunt, which can include orb weavers. Hunting down dangerous game requires mental processing. Should you make the leap or stay hungry and live to fight another day.
This video by Stephanie Sammann goes into all of the science behind jumping spider intelligence much more in depth.
Ending
So might as well jump, always spare the horses, and solve basic puzzles even if you have a tiny, tiny brain like the regal jumping spider here in LDT.