Although most moths do not bite, rare species from the genus Calyptra do sometimes bite human beings to feed on their blood, according to DermNet NZ. Usually, however, moths do not actively attempt to harm human beings or other mammals.
Rather than bite, most moths defend themselves passively with hairs and/or sharp spines capable of passing along toxins and irritating human skin, reports DermNet NZ. Generally a person must come into direct contact with moths to provoke such a reaction. Some large moths have spurs on their legs that are capable of penetrating human skin and causing urticaria, dermatitis or stings.