Collection of eels of the families Muraenidae and Congridae is often hampered by logistical and procedural difficulties. Sea kraits of the genus Laticauda may be useful bioassays for moray and conger eels in the western Pacific Ocean. Some widely distributed species of Laticauda appear to prey exclusively on eels, and these eels are readily palpated from snakes after they return to land to digest their prey. We removed 79 eels from 276 snakes on the island of Efate, Republic of Vanuatu, during November and December of 2000. Species diversity inferred from these eels was markedly different from the diversity inferred from eels from Vanuatu deposited in the Australian Museum, perhaps reflecting differential abilities of snakes and humans to capture certain eel species. This bioassay technique is inexpensive and logistically simple and may prove complementary to more traditional collecting methods.