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.
Flat warts are tumor-like masses on skin, slightly elevated above its surface. They are called flat because they look like a flat growth resembling a small nettles sting or a light mole. Flat warts are also called juvenile warts because they occur in childhood and adolescence, mostly in adolescence. And over time, during puberty, they disappear on their own and occur no more. Flat warts are usually located on the face, on the neck, on legs, on hands and on fingers of a young man or woman.