Here Strickland lived, coming seldom to Papeete, on the produce of the land. There was a little stream that ran not far away, in which he bathed, and down this on occasion would come a shoal of fish. Then the natives would assemble with spears, and with much shouting would transfix the great startled things as they hurried down to the sea. Sometimes Strickland would go down to the reef, and come back with a basket of small, coloured fish that Ata would fry in cocoa-nut oil, or with a lobster; and sometimes she would make a savoury dish of the great land-crabs that scuttled away under your feet. Up the mountain were wild-orange trees, and now and then Ata would go with two or three women from the village and return laden with the green, sweet, luscious fruit. Then the cocoa-nuts would be ripe for picking, and her cousins (like all the natives, Ata had a host of relatives) would swarm up the trees and throw down the big ripe nuts. They split them open and put them in the sun to dry. Then they cut out the copra and put it into sacks, and the women would carry it down to the trader at the village by the lagoon, and he would give in exchange for it rice and soap and tinned meat and a little money. Sometimes there would be a feast in the neighbourhood, and a pig would be killed. Then they would go and eat themselves sick, and dance, and sing hymns.

这里eat themselves sick 怎么分析理解？