Content

• To step
• Part 1 of 3: Finding water bears
• Part 2 of 3: Organizing the habitat for the water bear
• Part 3 of 3: Taking care of water bears
• Tips
• Warnings
• Necessities

"Water bears" is the common name for tiny, multicellular creatures that have always amazed microscopists. Their real name is tardigrada ("slow runners"). With four pairs of stubby legs and a choppy step, they look a bit like microscopic bears (eight-legged microscopic bears).Water bears live in more places on earth than humans do, so in fact every handful of water probably contains some water bears. The easiest way to find and care for them, however, is to dig into patches of wet moss.

To step

Part 1 of 3: Finding water bears

1. Learn about water bears. These creatures may be microscopic, but they are also a lot of fun! Water bears are one of the most amazing animals on the planet, living just about any place you can think of. They can survive the following:
   • Temperatures as low as -200 ° C and as high as 151 ° C
   • Freeze in a block of ice
   • Lack of oxygen, for days and possibly months
   • Lack of water, for decades
   • X-rays up to 1,000 times the lethal dose for humans
   • Lots of harmful chemicals
   • Boiling alcohol
   • Low pressure of a vacuum, such as that in space
   • Extreme pressure, up to six times the pressure in the deepest part of the ocean
   • Note that they can only survive these conditions in cryptobiosis. If you expose a live water bear to these conditions, it would die instantly.
2. Find a moist habitat for water bears. Many water bears are aquatic animals, but the easiest place to find them is in damp moss, lichen and leaf litter. Search in forests and around ponds or even just in your backyard. You have the best chance if you look in damp places where water bears are active. You can take a sample from a dry habitat if nothing else, as it can contain water bears in extreme sleep (cryptobiosis) waiting for water to rejuvenate.
3. Take a sample of moss or lichen with tweezers. Place the sample in a paper bag or envelope to allow it to dry a little. (A plastic bag will trap the water and encourage mold growth, which will block your view of the creatures.)
   • You can take samples of different types of moss, lichen, or leaf litter to see if the water bears like any of these more than the rest.
   • Soft lichen is more likely to contain water bears than hard, crusty lichen. You can even find water bears in the powdery lichen that grows on stone and brick walls.

Part 2 of 3: Organizing the habitat for the water bear

1. Place the samples in a Petri dish. You only need a little bit of each material in each petri dish. If you don't have a petri dish, you can use any small clear plastic container. Pressure packs that once contained pills are a good option.
2. Soak the moss or lichen completely. Add water, preferably distilled water or rainwater, until there is an inch of water in the bowl. Let it soak for eight to 24 hours to get the water bears active.
3. Squeeze the water from the moss into a new Petri dish. Squeezing or shaking out their habitat will transfer the microscopic creatures to the water.
4. Find a low power microscope. Most water bears are about a quarter to half a millimeter long. That's almost within the sight of the human eye. You only need a magnification of 15x or 30x to see a water bear. If you don't have a microscope, buy a cheap stereo microscope online.
5. Find the water bears. Set the microscope over the Petri dish and set the focus on the moss. It helps to shine a powerful flashlight horizontally through the side of the petri dish. This will cause the water bears and other creatures to glow white. Look for an animal with four pairs of stubby legs that moves slowly back and forth to propel its muddy body. The last pair of legs face back, so you may mistake it for a tail or the end of the body.
   • If there is a water bear, you have the jackpot. Pour the water back into the moss to give it a living environment.
   • If you don't see any water bears after moving the Petri dish back and forth for a while, pour the water back and try again with a different kind of moss until you find one.

Part 3 of 3: Taking care of water bears

1. Feed the water bear. Water bears suck the juices from moss, algae and lichens for food. Add a little plant matter to the habitat once a month or replace the old material when it starts to mold or decompose.
   • Water bears also eat nematodes (small worm-shaped creatures) and rotifers (small plankton). Try to find good, wet moss for the water bears, as that will likely contain their prey.
   • Some water bears live in fresh water and others in salt water. So stick to water and plants from the same type of environment as where you found your water bear.
2. Replace the water in the Petri dish when it has dried. Water bears usually survive a dry environment, but not always. Be kind to your water bears and keep them wet.
   • Dried water bears are smaller and completely immobile. You may not see them, but you will be able to see them again if you soak them nicely.
3. Enjoy taking care of your water bears. They don't mind if you look at them through the microscope every now and then. If you're lucky you may also see them shed their hard outer shell, lay eggs, or hatch.

Tips

• The bigger the container you keep the water bears in, the happier they will be. The colony may become gigantic after a while.
• Be aware that some water bears eat other water bears.
• After you soak the moss, don't let all the water sit. Feel free to drain a little.
• Examine moss under the microscope to determine if there are nematodes on it so that your water bears can eat.
• Although water bears are one of the toughest organisms on Earth, don't expose them directly to radiation, temperature extremes, or extreme conditions. They can usually survive, but it is not good for them.
• Beach sediment also often contains water bears. These are specific species that prefer salt water, so get water from the sea if you keep them as pets.
• There are more than 1,000 different species of water bears, which have a whole tribe (phylum) to themselves. In comparison, humans come under the tribe of Chordata, as do mammals, fish, amphibians, and reptiles, along with sea squirts and many other oddities!
• If you see colors in your water bear, you are looking into its belly! Water bears are mainly transparent, so you can see the color of recently eaten food.

Warnings

• While looking for water bears, be aware of the environment. Don't disturb animals and leave everything as you found it.

Necessities

• Tweezers (for grasping)
• Paper bag
• Petri dish
• Damp moss, lichen or leaf litter
• Rain or distilled water
• Microscope
• Flashlight
• Nematodes