Hiking in Panama is an incredible experience because the forest is absolutely packed with life. You can walk beneath towering trees while monkeys move through the canopy, hear frogs calling from hidden streams, watch butterflies disappear into the vegetation and suddenly notice a giant centipede crossing the trail. But a tropical forest also comes with a few creatures that are much more interested in you than you are in them. Mosquitoes, ticks, horse flies, ants, wasps, centipedes, scorpions and other biting or stinging creatures are all part of the experience. Most are more annoying than dangerous, but knowing what to watch for makes hiking much more comfortable.
Mosquitoes are probably the most obvious pest. Panama has many mosquito species, and some can transmit diseases including dengue, Zika and chikungunya. Malaria is also present in some parts of Panama, although the risk varies considerably by region. Different mosquitoes are active at different times, so don't assume that mosquitoes are only a problem at sunset. Some species are active during the daytime, while others are more active around dusk and during the night. A good insect repellent containing DEET, picaridin or another recognized active ingredient is one of the easiest ways to make a jungle hike more enjoyable. Long, lightweight clothing is also useful, particularly when hiking through dense vegetation.
Ticks are another one to take seriously, partly because they are so easy to miss. Unlike mosquitoes, you may never notice a tick attaching itself to you. They are particularly associated with vegetation, tall grass, forest edges and leaf litter. A tick can climb onto your shoes or clothing and eventually find a warm area of exposed skin. After hiking, especially if you've been walking through dense vegetation, it is worth checking your ankles, legs, waist, behind your knees, armpits, around your ears and through your hair. Check your clothing and backpack as well. Finding a tick doesn't automatically mean you've caught a disease, but removing it promptly is sensible.
Horse flies are another tropical hiking nuisance that people sometimes underestimate. These are much larger and more noticeable than mosquitoes, and their bites can be surprisingly painful. Unlike mosquitoes, which use a relatively delicate feeding structure, female horse flies have mouthparts adapted for cutting the skin and feeding on blood. You often know immediately when one has landed on you because it can feel like someone has pinched you. Horse flies are especially annoying around open areas, rivers, wetlands, livestock and sunny forest clearings. They can be persistent, and swatting at them sometimes seems to encourage them rather than discourage them. Long pants and shirts can help, although a determined horse fly can occasionally find exposed skin anyway.
No-see-ums and biting midges are another reason tropical evenings can become itchy. These tiny insects can be almost impossible to spot, and you may feel their bites long before you figure out what caused them. They can be particularly noticeable around damp areas, vegetation and still water. Panama also has sand flies, some of which can transmit leishmaniasis. For travelers, the practical solution is much the same as with mosquitoes: use repellent, cover exposed skin when appropriate and don't spend unnecessary amounts of time sitting motionless in areas where biting insects are particularly active.
Then there are the ants, and Panama has an extraordinary variety. Most ants you encounter are completely harmless and fascinating to watch, but some can deliver painful bites or stings. Fire ants are particularly worth avoiding. The biggest mistake isn't usually noticing one ant walking across the trail; it's accidentally standing on an entire colony. Be careful where you put your feet when stopping for a rest, especially around disturbed soil, grassy areas and the bases of trees. And if you see thousands of ants suddenly pouring out of a hole or moving across the ground, that's probably a good indication that you shouldn't put your backpack down there.
Wasps and bees deserve similar respect. A wasp flying past you isn't necessarily interested in you at all. Problems usually arise when a person accidentally gets close to a nest or disturbs it. Tropical wasp nests can be hidden in vegetation, underneath structures, inside cavities or attached to branches. If you notice numerous wasps repeatedly entering and leaving one particular location, simply give that area a wide berth. There is no reason to investigate a mysterious buzzing sound in the jungle with your face six inches from the source.
Centipedes are some of Panama's more impressive nighttime predators. Large centipedes, particularly species in the genus Scolopendra, can become surprisingly large. They aren't insects; they're members of the group Chilopoda, and their first pair of legs has evolved into venom delivering structures called forcipules. They use them to subdue insects, spiders and other small animals. A large centipede can deliver a very painful bite, but it isn't interested in hunting humans. If you see one crossing a trail, simply let it continue on its way. The same applies if you discover one underneath a log or rock. Don't pick it up.
Scorpions are another creature you might encounter, particularly during nighttime walks. They are generally secretive and spend much of the day hiding before becoming active after dark. Finding one doesn't mean the trail you're on is dangerous. It means you're walking through a tropical ecosystem with predators that have evolved to operate at night. Use a flashlight, watch where you put your hands and don't reach blindly underneath rocks, pieces of wood or vegetation. As with centipedes, the easiest strategy is to admire them without touching them.
Millipedes look much more threatening than they generally are. They are often confused with centipedes, but most millipedes are peaceful decomposers that eat dead leaves and other organic material. They move slowly and many curl themselves into a spiral when disturbed. They don't have the venomous forcipules of centipedes, but some species can release irritating defensive chemicals. This means you shouldn't pick one up and then rub your eyes or face. In the jungle, it is usually better to leave unfamiliar creatures exactly where you found them.
And then there is the animal that isn't a pest but should always be on your mental checklist when hiking in Panama: the snake. Panama has numerous snake species, including venomous ones. Fortunately, most snakes want absolutely nothing to do with people and will try to escape rather than confront a hiker. The main danger is accidentally stepping on one or reaching into vegetation, a hole or a rock crevice without looking first. Wearing proper footwear, watching the trail and using a flashlight after dark are simple precautions. If you encounter a snake, give it plenty of room and never attempt to catch or handle it.
There is also a much less exotic danger that is easy to forget when you're busy looking for wildlife: the tropical heat. Panama can be extremely hot and humid, and even a relatively modest hike can become strenuous. Drink regularly, protect yourself from the sun and don't underestimate how much energy you are using. A trail that looks easy on a map can feel very different when you're walking uphill in hot, humid weather.
The best strategy for dealing with Panama's jungle pests isn't to become terrified of every six legged creature you see. It is simply to develop a few good habits. Use insect repellent, wear appropriate clothing, wear closed shoes, check yourself for ticks after hiking, shake out shoes and clothing that have been sitting outside, use a flashlight after dark and don't put your hands somewhere you haven't looked first. Those habits eliminate a huge amount of unnecessary trouble.
And remember that the overwhelming majority of the creatures you encounter aren't actually interested in you. The mosquito wants a blood meal, the horse fly wants a blood meal, the centipede wants a cockroach, the spider wants an insect and the snake generally wants to disappear before you even notice it. You're simply passing through their home.
That's part of what makes hiking in Panama so fascinating. The forest isn't a theme park where the animals appear on schedule. It is a living ecosystem operating around you, above you, beneath your feet and sometimes in the vegetation beside the trail. Most of the time you are simply an observer. Occasionally, however, something small will decide that you are lunch.