( ( Once ingested ) ( , ( ( ( ( methanol , ) ( which ( is ( ( wood alcohol ) ( that ( ( killed or ) ( blinded ( thousands ( of ( skid ( row drunks ) ) ) ) ) ) ) ) ) ) ) , ) ( ( converts ( to ( ( ( formaldehyde , ) and ) ( ( then ( formic acid ) ) ( which ( is ( ant ( sting poison ) ) ) ) ) ) ) ) . ) ) ) )
(ROOT (S (SBAR (IN Once) (S (VP (VBD ingested)))) (, ,) (NP (NP (NN methanol)) (, ,) (SBAR (WHNP (WDT which)) (S (VP (VBZ is) (NP (NP (NN wood) (NN alcohol)) (SBAR (WHNP (WDT that)) (S (VP (VP (VBD killed)) (CC or) (VP (VBD blinded) (NP (NP (NNS thousands)) (PP (IN of) (NP (NN skid) (NN row) (NNS drunks)))))))))))) (, ,)) (VP (VBZ converts) (PP (TO to) (NP (NP (NN formaldehyde)) (, ,) (CC and) (NP (NP (RB then) (JJ formic) (NN acid)) (SBAR (WHNP (WDT which)) (S (VP (VBZ is) (NP (NP (NN ant)) (VP (VBG sting) (NP (NN poison))))))))))) (. .)))
Once ingested, methanol, which is wood alcohol that killed or blinded thousands of skid row drunks, converts to formaldehyde, and then formic acid which is ant sting poison.
(ROOT (S (NP (JJ Formic) (NN acid)) (VP (VBZ is) (VP (VBN found) (PP (IN in) (NP (NP (DT the) (NNS secretions)) (PP (IN of) (NP (JJ stinging) (NNS ants))))))) (. .)))