Humans are ureotelic because it excretes urea as a waste product. Urea is less toxic than ammonia so it can be stored in the body for longer duration. The extra proteins in the body are degraded by the process of deamination where the NH2 group is removed and it is converted into ammonium ions in the liver. The ammonium ions enter urea cycle and get converted into urea. The urea formed in liver is transported to kidney through circulation and finally gets excreted.