Know how to use "fewer" and "less"? Find out.
Acanthocephala A·can·tho·ceph·a·la (ə-kān'thə-sěf'ə-lə)
Any of various worms of the phylum Acanthocephala that live parasitically in the intestines of vertebrates and are characterized by a cylindrical, retractile proboscis that bears many rows of hooked spines. Also called spiny-headed worm.