( Some ( ( can ( be ( ( heterotrophs , ) ( excess food ) ) ) ) . ) )
(ROOT (S (NP (DT Some)) (VP (MD can) (VP (VB be) (NP (NP (NNS heterotrophs)) (, ,) (NP (JJ excess) (NN food))))) (. .)))
Some can be heterotrophs, excess food.
(ROOT (S (NP (NNS Animals)) (VP (MD can) (RB not) (VP (VB produce) (NP (PRP$ their) (JJ own) (NN food)) (S (VP (VBG making) (S (NP (PRP them)) (ADJP (JJ heterotrophs)))))))))