( ( Ticks ( ( are not ) bugs ) ) ( , ( they ( ( are ( ( arachnids , ) ( which ( means ( they ( have ( 8 legs ) ) ) ) ) ) ) . ) ) ) )
(ROOT (S (S (NP (NNS Ticks)) (VP (VBP are) (RB not) (NP (NNS bugs)))) (, ,) (NP (PRP they)) (VP (VBP are) (NP (NP (NNS arachnids)) (, ,) (SBAR (WHNP (WDT which)) (S (VP (VBZ means) (SBAR (S (NP (PRP they)) (VP (VBP have) (NP (CD 8) (NNS legs)))))))))) (. .)))
Ticks are not bugs, they are arachnids, which means they have 8 legs.
(ROOT (S (NP (NNS Arachnids)) (VP (VBP have) (NP (NP (CD 4) (NNS pairs)) (PP (IN of) (NP (NNS legs))))) (. .)))