Wool is the ideal fiber for carpet. Its nubby texture and ability to hold its shape means that it can take a lot of foot traffic. This means years of durability despite lots of wear and tear. Wool also has properties that help keep soil and dirt at bay. The outer layer of the fiber has a waxed surface that keeps soil suspended at the top of the carpet so it's easily cleaned and vacuumed. Plus, it has a high moisture content that makes it naturally flame retardant, which is always a bonus in any home. Though many synthetic materials that mimic wool's traits have made their way onto the market, wool carpets are still readily available if you prefer a natural material in your house.
Despite its general resistance to stains, wool carpeting can still get them. It's tempting to want to get in there with a bristle brush and a stain remover, but it's best to start with plain water to see if that will help lift the stain. Spray water on the stain with a spray bottle in a light mist, and using a clean white towel, work from the outside of the stain to the center. This keeps whatever made the stain from spreading outward. Try blotting the stain first to see if that helps lift some of the residue.
If you need some stronger action, gently brush the carpet pile in one direction about 10 times, and then brush it in the other direction. It's important to never scrub carpet because the back and forth can permanently damage the pile. Repeat this motion until the stain is gone and then do a final light rinse. You'll want to use as little water as is needed and if you have to use a cleaning agent, be sure not to soak the area. Wool carpet is naturally full of moisture so you don't want to add more. If you're working with a particularly stubborn stain, you can treat it with a stain solution first. If you don't want to use chemicals, use a combination of water and dish detergent, or water and white vinegar. Apply it sparingly and let it sit for 10 or 15 minutes before starting to blot.