#1 If soap is biodegradable it's okay to use it in streams, rivers, and lakes.
Biodegradable soaps are great but they should never be used in or near streams or rivers as they can hurt the delicate aquatic ecosystem and harm the creatures that live there in even very small quantities. All soaps (even the biodegradable ones) can destroy the external mucus layers that protect fish and cause severe damage to gills. Soaps also kill fish eggs in very low concentrations, interfere with breeding, and cause freshwater algal blooms that deplete oxygen levels in the waterway. Make sure to always use soaps at least 200 feet away from any water source.
#2 Removing a tick with tweezers may leave the head in the skin so you should burn, freeze, or smother them with nail polish or petroleum jelly first to make them pull their heads out.
Ticks do not bury their heads in your skin, only their mouth parts penetrate. You should remove a tick as soon as possible after you find it using tweezers and then clean the area well using alcohol or soap and water. Grasp the tick as close to the skin as possible and pull gently upward with steady even pressure. Burning a tick or covering it with noxious liquids could make the tick regurgitate increasing the likelihood of infection with a tick-bourne disease.
#3 You should drink your pee if you don't have any water.
If you are out of water and to the point where you are considering drinking your own urine, chances are you are already pretty dehydrated. In a dehydrated person urine is extra concentrated with waste products that your kidneys have filtered out of your system. Adding these back to your body can put additional stress on your kidneys and the additional salts can actually accelerate dehydration.
#4 Daddy long-legs are the most poisonous spiders alive but their fangs are too short and their mouths are too small to bite humans.
Daddy long-legs (or harvestman spiders) do not possess venom glands or fangs. Their mouths are tiny grasping claws that are much too weak to break human skin.
#5 Moss always grows on the north side of trees.
While it is true that moss likes to grow in shady, cool, and damp locations the plant does not in fact have a compass. In the northern hemisphere the north side of a tree may get less sunlight and make for better growing conditions but many other factors also come into play, making the old adage a poor way to try and navigate.
#6 You should suck the venom out of a snake bite to keep it from getting into the bloodstream.
Snake venom spreads very quickly and it is very unlikely that cutting into a snake bite would reach the venom or that you would be able to suck hard enough to get enough venom out to make any difference. It will cause further harm to the victim though by introducing mouth bacteria into a brand new wound and could cause tissue damage to the mouth of the helpful friend. Tourniquets are also a bad idea as the potential dangers associated with a tourniquet far outweigh the benefits when it comes to snake bites. Bites from mature snakes can also be "dry" bites that do not result in venom being injected into the wound. If bitten by a snake seek appropriate care from medical professionals. Take a picture of the snake if you can do so without risk of further injury but do not attempt to catch it/kill it in order to take it with you.
#7 Handling toads can give you warts.
While many frogs and toads can have bumps on their skin you can't get warts from them; warts on humans are caused by a human virus. Some toads (like the Colorado River Toad below) do excrete a toxin through special glands in their skin that can be irritating if touched or deadly if ingested so you still shouldn't handle them.
#8 If you are lost finding food is the most important thing.
If you are lost in the woods food should be one of the last things you worry about. People can go weeks without food but only a few days without water or a few hours without shelter if the weather is bad. If it is hot find shade, if it is cold find someplace warm (or at least dry) and insulate yourself from the ground. A source of water should be your next concern.
#9 Running water is safe to drink.
There is nothing magical about fast moving water that makes it safe to drink. There could still be something rotting upstream or a variety of wild animals using that clear water for a rest stop. To be on the safe side you should still filter/boil/treat running water before drinking it. If you don't have the means to filter/boil/treat it by all means drink it if you have to. If there are bacteria/viruses/parasites in the water it can take days to a few weeks to make you sick while you can die of dehydration in just a couple of days.
#10 You'll sleep warmer in your sleeping bag if you aren't wearing any clothes.
If it's going to be a cold night you will want to put on a few dry layers before climbing into your sleeping bag. Some long underwear, wool socks, and a warm hat will do wonders keeping you toasty on cold nights by providing additional insulation to trap warmth next to your body. You can make your bag even warmer by adding a sleeping bag liner and extra clothes to take up any airspace in your bag. Be sure to use an air mattress or other pad to insulate you from the cold ground and remove any wet clothes before climbing in.
Do you know any other camping/outdoor myths? Let us know in the comments below.