( Hookworms ( ( ( are also ) parasites ) . ) )
(ROOT (S (NP (NNS Hookworms)) (VP (VBP are) (ADVP (RB also)) (NP (NNS parasites))) (. .)))
Hookworms are also parasites.
(ROOT (S (NP (DT A) (NN hookworm)) (VP (VBZ is) (VP (VBN classified) (PP (IN as) (NP (DT a) (NN parasite))))) (. .)))
A hookworm is classified as a parasite.