In one sentence, describe what the following article is about: When you obtain new shells for your hermit crab, it is very important for you to make sure the shells are safe and sanitary. You can do this by boiling your shells. First, use a brush to remove any sand or debris from in the inside and outside of your shell. Then, submerge your shells in boiling distilled water, and boil them for 15-20 minutes. After your shells have been boiled, they must be moistened with ocean water, or salt water. (Purchasing a saltwater solution from a pet store is the most effective option.) As you wait for your crab to select a new shell, you will want to periodically re-moisten the insides of your shells. This will draw you hermit crab toward the shells, and make the shells more attractive to him. Avoid tap water. Most tap water contains trace amounts of copper or other heavy metals. Hermit crabs are extremely sensitive to these metals, and they can hurt your crab. Once your shells have been properly prepared, place them where your crab can see them. Position them out in the open, on the ground level (substrate) of your crab's habitat, so that your crab will encounter them daily. Once a week (or every other week) you may want to remove the shells, wait a few hours, and then put them back. If your crab has become accustomed to the shells, he may not really recognize them anymore. Removing and reintroducing them may encourage your crab to investigate, and possibly even change shells. This is also a good time to re-moisten your shells with saltwater.
Summary: Boil new shells. Moisten shells with saltwater. Place shells where the crab can see them.

In one sentence, describe what the following article is about: While the clicker noise is good for letting the cat know what it's doing right, verbal cues can be used once the cat has already learned a few tricks, to help it understand which trick you want it to do. The verbal cue must be distinct and clear. It should be a word you won't use with other pets, or a word that is used too much in everyday conversation. Choose a logical word to make your cat do something. You might use "Jump!" for when your cat jumps onto something. You might use "Come!" for when your cat walks toward you. Sit on the floor and hold out the target. If your cat will respond to the target by walking toward it, try holding it in front of you and say, "Come!" at the same time. When your cat moves towards the target (and you), click and give a reward. Try this several times in different locations in your house. Make sure you click and reward each time. If your cat is just not getting it, or if he seems confused, revert back to your previous training. End the session on a good note and try again later. Remember to only try these sessions for about 5 minutes at a time. Hold a treat above his head in your closed hand. As he sees it, move your hand back further. Most cats will naturally sit down so their head can still follow the treat. As soon as your cat sits down (or even as he starts to sit down), click the clicker, say "Sit," and give him the treat. Repeat this several times a day. The verbal cue signals that when your cat performs a particular behavior, he will receive a reward. If your cat does this something on his own, just don't reward him. Don't click and don't give a treat. At this stage of the training, ignore any behavior that he does without a verbal cue. This is so your cat will associate the verbal cue with the click and reward. As you continue to train your cat, he will learn more commands and will recognize different verbal cues for different tricks. At some point, you'll find you don't need the clicker or the treats anymore.
Summary: Decide on a verbal cue for each of your cat's tricks. Teach your cat to come. Teach your cat to sit. Ignore behavior performed without a verbal cue. Repeat this process with other tricks.

In one sentence, describe what the following article is about: If you've uploaded a video to Wuala, tap on it in the "Wuala" file browser.
Summary:
Tap on the video file. Select the default player you want to use. Watch and enjoy.