Edgar Rice Burroughs 
Tarzan and the Ant Men [EPUB ebook] 

No one had ever crossed the Great Thorn Forest until Tarzan of the Apes crashed his plane behind it. Within lay a beautiful country. But in it lived the Alali, strange stone-age giants whose women regarded all men as less than slaves. And beyond the Alali lay the country of the Ant-Men — little people only 18 inches tall. There, in Trohanadalmakus, Tarzan was an honored guest—until he was captured by the warriors of Veltopismakus in one of the Ant-Men’s many wars. They had plans for the ape-man. They shrunk Tarzan to their size and set him to work as a quarry slave. Tarzan’s only hope is to make a daring escape. But what can an 18 inch tall man do?