Walk through a Panamanian rainforest after dark and you quickly discover that the jungle has a completely different personality at night. The frogs begin calling, insects appear everywhere, moths fly toward your flashlight, and creatures that spend the entire day hidden beneath leaves, logs and rocks suddenly emerge to hunt. Among the strangest animals you can encounter is the whip scorpion, sometimes called a vinegaroon.
And yes, they occasionally turn up on the night walk at Lost and Found Hostel. They are exactly the sort of creature that makes a nighttime walk through the forest so much more interesting. At first glance, a whip scorpion can look like something that escaped from a science fiction movie: a dark, heavily armored body, enormous pincers, extremely long feeler legs and a thin whip like tail extending behind it.
Despite the frightening appearance, whip scorpions are not true scorpions, and they are not venomous. They belong to their own arachnid order, Thelyphonida. Around the world there are roughly a hundred or more described species, with most occurring in tropical and subtropical environments. They are particularly associated with warm, humid forests and other places where there is plenty of cover and moisture.
They look dangerous, but they really aren't
The first thing people usually notice is the pair of enormous front pincers. These are called pedipalps, and they look remarkably similar to the claws of a scorpion. They aren't simply weapons, however. Whip scorpions use these powerful appendages to grab and manipulate prey.
The next strange feature is their front pair of walking legs. Instead of using these like ordinary legs, whip scorpions hold them out in front of their bodies and use them almost like extremely long antennae. These legs are packed with sensory structures that help the animal navigate its surroundings, locate prey and detect obstacles in the darkness.
This is particularly important because whip scorpions are primarily nocturnal and their eyesight is not their main way of understanding the world. When you see one moving through the forest at night, you may notice those long front legs constantly sweeping around in front of it. It is essentially feeling its way through the jungle.
Then there is the famous whip.
The thin tail like structure extending from the back is called a flagellum. It isn't a stinger and it isn't a weapon like the tail of a true scorpion. It is another sensory structure that helps the animal gather information about its surroundings.
So the animal that looks like a cross between a scorpion, spider and alien has actually evolved a remarkably specialized collection of sensory equipment for living in the darkness.
Why are they called vinegaroons?
This is probably the most entertaining part of their biology.
When seriously threatened, many whip scorpions can release a defensive chemical spray from glands near the base of the flagellum. The spray contains acetic acid, the same chemical responsible for the characteristic sharp smell of vinegar. That is where the nickname vinegaroon comes from.
The spray is primarily a defense against predators. It is not venom delivered through a stinger and whip scorpions don't inject poison into their prey.
For humans, the spray is generally not considered dangerous to normal skin, although getting it into the eyes or other sensitive areas can be extremely unpleasant.
So if somebody sees a whip scorpion on a Lost and Found night walk, the best response isn't to poke it, corner it or pick it up for a photograph. Give it some space and let it continue doing what it has been doing for millions of years.
The nighttime hunter
Whip scorpions spend daylight hours hiding in dark, protected places. Depending on the species and habitat, they may occupy burrows, spaces underneath rocks and logs, rotting wood, leaf litter or other sheltered locations.
When darkness arrives, they become active.
They are predators, and their diet can include insects and other small ground dwelling creatures such as beetles, crickets, ants, caterpillars and other arthropods. They use their sensitive front legs to locate things and their powerful pedipalps to capture and manipulate prey.
The jungle floor is basically their hunting ground.
And this is one reason night walks are so fascinating. During the day, you might walk past the same log without seeing anything. At night, that log can suddenly become a miniature ecosystem.
Their life cycle is incredibly slow
One of the most fascinating things about whip scorpions is that they don't grow rapidly like many insects.
Their life cycle can take years.
The exact timing varies between species, and some of the best detailed life history information comes from North American vinegaroons rather than Panamanian species. So it is important not to assume that every whip scorpion in Panama follows exactly the same timetable.
Nevertheless, the general pattern is remarkable.
Stage one: finding a mate
Whip scorpion reproduction is far more complicated than you might expect from an animal that looks like a giant bug.
The male and female don't simply encounter each other and immediately mate. Courtship can involve elaborate movements and physical interactions that may continue for many hours.
In some studied species, the male and female grapple and move together while the male uses his sensory appendages and pedipalps to interact with the female. Eventually the male produces a spermatophore, a package containing sperm.
The female is guided toward this sperm package and the sperm is transferred into her reproductive system. Some documented courtship sequences can last many hours, with one well studied species averaging almost 13 hours.
Imagine finding two whip scorpions doing this on the forest floor during a Lost and Found night walk. You wouldn't just be looking at two creepy looking creatures. You could potentially be witnessing one of the most complicated moments in their entire life.
Stage two: the female prepares for motherhood
After mating, the female eventually prepares a protected underground chamber.
This is where things get particularly unusual.
Rather than simply laying her eggs somewhere and wandering away, the female becomes intensely involved in protecting her developing offspring. She produces a membranous egg sac attached beneath her abdomen. Depending on the species, the clutch can contain several dozen eggs.
During this period the female may remain inside her burrow and can stop feeding while she protects the developing brood.
This is a vulnerable period for her because she cannot simply leave whenever she wants.
She is essentially turning her underground burrow into a nursery.
Stage three: the eggs develop
Inside the protected egg sac, the embryos develop.
The female has to maintain the right conditions for them, particularly protection from drying out. This is especially important for tropical arachnids because their tiny developing offspring are vulnerable to environmental changes.
Eventually the eggs hatch.
And this is where whip scorpion parenting gets really strange.
Stage four: the babies climb onto their mother
The newborn whip scorpions are not immediately independent.
The young climb onto their mother's body and cling to her.
They are initially pale or whitish and look nothing like the dark, tough adults people encounter on nighttime walks. They remain associated with their mother while they undergo their first molt.
This is one of the most remarkable sights in the world of arachnids.
Imagine shining a flashlight into a burrow and discovering a female whip scorpion covered with dozens of tiny pale babies.
The mother isn't simply a container for the eggs. She provides an actual period of maternal protection.
In some studied species, the mother also provides food for the young. Research on the giant vinegaroon, for example, has documented mothers feeding prey to their offspring.
Stage five: the first molt
The first molt is a major turning point.
The young whip scorpions eventually shed their juvenile outer covering and become much more recognizable as miniature versions of adults.
After this first molt, they begin becoming independent and eventually leave their mother's protection.
Molting is absolutely essential because an arthropod's external skeleton doesn't expand continuously like the skin of a mammal. The animal has to produce a new, larger exoskeleton and shed the old one.
And this is a dangerous time.
Immediately after a molt, the new exoskeleton is soft. The animal is vulnerable until the new outer layer hardens and becomes properly pigmented. Studies of giant vinegaroons have documented newly molted individuals remaining pale for several days, with full hardening and pigmentation taking considerably longer.
They spend years growing up
This is perhaps the most surprising part of the entire story.
A whip scorpion isn't born, grows for a few weeks and becomes an adult.
It can take several years to reach maturity.
Detailed research on vinegaroons has found four free living immature stages before adulthood, with each stage potentially lasting a year or more. In one well studied species, the normal lifespan from egg to death is approximately seven to nine years.
Another source on giant whip scorpions reports at least seven years of life, with several years spent growing before adulthood.
That means the strange creature you encounter crossing a trail at Lost and Found could have been living in the forest for years before you ever noticed it.
And there is another fascinating aspect to this.
Molting can take months to prepare for
Before molting, a whip scorpion can enter a prolonged preparation period.
The animal may create a protected molting chamber and remain there while the new exoskeleton develops. During this period it can become extremely inactive and may stop feeding. Eventually the old exoskeleton splits and the animal emerges in its new form.
So when you see an adult whip scorpion walking confidently across the forest floor, you're seeing the end result of years of growth and multiple dangerous transformations.
Adults are built for the night
Once mature, whip scorpions become efficient nocturnal predators.
Their bodies are heavily armored, their pincers are powerful, their sensory legs constantly probe the darkness and their flagellum provides additional sensory information.
They don't need to chase everything they encounter.
Instead, they can move slowly through the darkness, constantly gathering information about what is around them.
This is one reason a night walk can reveal so many strange behaviors that you would never see during the day.
The rainforest isn't actually becoming more alive at night.
You are simply finally seeing the animals that were hiding from you all day.
Whip scorpions in Panama
Panama is an excellent environment for animals like whip scorpions because much of the country provides the combination they need: warmth, humidity, forest cover, leaf litter, rotting wood, rocks and abundant small prey.
The exact species found in Panama depends on location and habitat, and identification can require examination of anatomical details rather than simply looking at a photograph.
That is important because "whip scorpion" isn't a single species. It is a whole group of arachnids.
The animals people encounter in Panama can therefore look somewhat different from the giant vinegaroons that are famous in parts of the southwestern United States.
But the basic body plan is unmistakable: big pedipalps, long sensory front legs, armored body and the characteristic whip like flagellum.
And yes, you can sometimes see them at Lost and Found
One of the fun things about the Lost and Found Hostel night walk is that you aren't walking through an artificial wildlife attraction.
You are walking through actual forest.
That means there is no guarantee that a particular animal will appear on a particular night. Wildlife doesn't operate on a schedule designed for tourists.
Sometimes you might see frogs everywhere.
Another night you might encounter insects, spiders, sleeping birds, mammals or something much stranger.
And occasionally, a whip scorpion appears.
When the beam of a flashlight hits one, the first reaction is usually something along the lines of:
"What the hell is THAT?"
Then you start noticing the details.
The strange front legs.
The huge pincers.
The thin tail.
The slow deliberate movement.
And suddenly what looked like a miniature monster becomes one of the most interesting animals of the night.
The Lost and Found night walk is particularly suited to finding creatures like this because whip scorpions are primarily nocturnal. They are exactly the sort of animal that can remain practically invisible during a daytime hike and then suddenly appear on the trail after dark.
Are they dangerous?
For travelers, probably the most important thing to understand is that whip scorpions are not true scorpions and do not have the venomous stinger people associate with scorpions.
Their defensive strategy is completely different.
They rely on their armored bodies, powerful pedipalps, speed and their unpleasant chemical spray.
The spray is designed to discourage predators rather than hunt prey.
So the sensible approach is simple: admire them without handling them.
There is absolutely no reason to pick up a strange rainforest arachnid when you can take a photograph from a safe distance and let it continue hunting.
The hidden life beneath the rainforest floor
Perhaps the coolest thing about whip scorpions is that the animal you see for thirty seconds on a night walk represents only a tiny fraction of its existence.
Most of its life is hidden.
It may spend the daylight hours underground or beneath forest debris. It may spend months preparing for a molt. It can spend years progressing through juvenile stages. A female can devote an enormous amount of effort to producing and protecting a relatively small number of offspring.
And then, one humid night, it walks out onto the forest floor.
That is why finding a whip scorpion in Panama is more interesting than simply finding another "bug."
You're looking at an animal with an ancient evolutionary history, extraordinary sensory adaptations, elaborate courtship, maternal care, chemical defenses and a life cycle that can stretch across many years.
And occasionally, while everyone else at Lost and Found is looking for frogs, snakes, tarantulas or sleeping birds, one of these bizarre little jungle predators quietly walks across the trail.
You shine your flashlight on it.
It freezes.
Its long sensory legs begin moving.
The whip at the back flicks slightly.
And for a few seconds, everyone gets to meet one of the rainforest's strangest nighttime residents.