Inside the navel can be pulled out, because the navel inside the usual dirt and other situations, it is easy to hide bacteria, especially anaerobic bacteria, so regular pulling out to clean the dirt inside is necessary. If pulling must wait for the inside of the dirt completely wet, you can use water or disinfectant water to completely wet, softened, and then use blunt objects such as cotton swabs to remove, it is better to avoid the application of sharp or finger nails to pull out, if accidentally damage the mucous membrane or skin inside the navel, it is easy to lead to bacterial infection.