▁yellow ▁transl uc ent ▁hands . ▁Their ▁skin ▁has ▁d ots ▁which ▁matches ▁that ▁of ▁the ▁leaves ▁in ▁the ▁area . ▁ ▁When ▁confront ed ▁or ▁approached , ▁they ▁tend ▁to ▁free ze ▁up ▁and ▁not ▁move . ▁It ▁is ▁not ▁specifically ▁known ▁what ▁the ▁glass ▁f rog ▁e ats , ▁but ▁it ▁is ▁assumed ▁that ▁they ▁feed ▁on ▁small ▁insect s . ▁ ▁Also ▁known ▁as ▁the ▁Northern ▁G lass ▁F rog , ▁this ▁f rog ' s ▁physical ▁features ▁include ▁primarily ▁green ▁skin , ▁pale ▁yellow ish ▁sp ots , ▁yellow ▁f ing ert ips ▁and ▁transl uc ent ▁skin ▁covering ▁its ▁st om ach . ▁A ▁sheet ▁of ▁gu an ine ▁st ret ches ▁over ▁several ▁internal ▁org ans , ▁such ▁as ▁the ▁heart , ▁but ▁leaves ▁others ▁parts ▁such ▁as ▁the ▁li ver ▁exposed ▁for ▁view ing ▁as ▁it ▁only ▁covers ▁half ▁of ▁the ▁f rog ' s ▁under bel ly . ▁They ▁also ▁possess ▁a ▁white ▁vocal ▁sac ▁that ▁can ▁be ▁used ▁to ▁produce ▁sounds ▁for ▁m ating . ▁Male ▁fro gs ▁have ▁a ▁notice able ▁hook ▁pro tr ud ing ▁from ▁its ▁sp ine , ▁pres umably ▁used ▁to ▁fight ▁other ▁fro gs , ▁defend ▁its ▁territory ▁or ▁the ▁eggs . ▁They ▁are ▁fier ce ▁f igh ters ▁who ▁will ▁occasionally ▁eng age ▁in ▁a ▁wrest ling ▁match ▁with ▁other ▁intr ud ing ▁fro gs . ▁The ▁female ▁species ▁are ▁slightly ▁larger ▁and ▁la cks ▁this ▁particular ▁feature . ▁ ▁There ▁have ▁been ▁more ▁than ▁ 1