There is nothing more annoying than washing your hands or brushing your teeth at the bathroom sink and watching as the bowl fills up from the running water. It should be flowing down the drain, but something has caused it to clog for the umpteenth time. Here are four potential causes of a clogged bathroom sink. Knowing the source will help in preventing trouble in the future. Soap You wouldn’t think of soap as being a problem in drain pipes, but it certainly is. Bar soap is the worst for clogging a sink. It may be in liquid form as it enters the drain, but once the water stops flowing, so does the soap. It can dry along the sides of the pipes where it can snag hair or dried skin. Consider switching to liquid soap. Cats If you own an indoor cat, he or she could be the culprit in a recurring clogged drain. A favorite area for cat napping is a nice, cool bathroom sink. You may not realize that your cat is enjoying a siesta in the bowl until clogging occurs. Hair can easily make its way through the stopper and build up in no time. Use a dampened paper towel and wipe around the bowl of the sink. You may find signs of your cat. If so, make sure the stopper is closed when you leave. Stopper When is the last time that you removed your bathroom sink stopper and thoroughly cleaned? You may be surprised to find a large amount of soap scum, hair or grease clinging to the underside of the stopper. This is an easy fix and one that can save you lots of frustration. Make a note to check the drain stopper in your routine cleaning for dirt and debris. Kids Kids can get into all sorts of mischief when left alone for a few minutes. They love to explore and try new things. Will a Band-Aid or sucker stick go down the drain? They may see these items disappear with ease. What they do not see is the object getting lodged in the pipe elbow. Keep a close eye on your kids, and make sure to teach them of the adverse consequences of putting objects down the drain. A bathroom sink can easily become clogged with a variety of elements. Watch for any build-up of water and tackle the problem quickly. The problem will only worsen if it is left untreated, potentially requiring the professional help of a bathroom plumber. Consider these four causes and take the proper steps to eliminate future problems. Determining the cause can save a lot of time and frustration. Lizzie Weakley is a freelance writer from Columbus, Ohio. In her free time, she enjoys the outdoors and walks in the park with her three-year-old husky, Snowball.