The island in Lord of the Flies is teeming with wildlife and vegetation. The boys on their very first day together discover a pig trail as a possible food source as well as fruit trees. As for snakes, many of the younger boys fear "a snake thing. Ever so big" (35). The older boys originally are quick to scoff and dismiss this notion as one of the littluns getting tangled up in the creeper vines.
Although none of the boys ever encounter an actual snake in the jungle, their fear of the unknown and the possibility of such a "beastie" lurking in the dark will persist in their nightmares and establish a climate of fear on the island.
No. When in the book the little'uns said snakes they were refering to the fire. The only wild animals would be the pigs.