Class Trematoda: Infect the internal organs of hosts. Parasitic Can be endoparasites (live in the host) or ectoparasites (attach to external surfaces of the host. Size: ~ 1 cm to 10 cm Covered in an unciliated cuticle. Usually require 2 hosts to complete it's life cycle.
Warts are generally caused by a human virus known as papilloma while moles are generally related with age and caused by hormones and environmental factors. There are cases when kids are born with moles but in general moles on the face increase with increase in age.
A wart is a skin growth caused by some types of the virus called the human papillomavirus (HPV). HPV infects the top layer of skin, usually entering the body in an area of broken skin. The virus causes the top layer of skin to grow rapidly, forming a wart. Most warts go away on their own within months or years. Warts can grow anywhere on the body, and there are different kinds. For example, common warts grow most often on the hands, but they can grow anywhere.