They had a varied diet, eating whatever raw game they could catch, including squirrels, small deer, tortoises, lizards, and sometimes even crocodiles.
[1] During an exploration of caves at Kudimbigala, army captain A. T. Rambukwelle discovered a stone building, "reminiscent of the miniature Stonehenge" in the forest.
[6] Villagers reported the creature to be totally black, gorilla faced and having long claws which was different from the Veddah descriptions, leading to the possibility of a fraud.
Some sort of Sri Lankan gibbon was regarded by both him and Bernard Heuvelmans as a fairly good candidate, as these animals do conform to the nittaewo's description in a number of ways.
Although a far cry from the savage nittaewa, which was said to disembowel people and kill crocodiles, Heuvelmans notes that the Veddahs may simply have "blackened the character of the greatest enemy".
Orangutans have sometimes been reported from mainland India, but Heuvelmans notes that this ape is too large, heavy, arboreal, vegetarian, and solitary to make a good nittaewa identity.
South and Southeast Asia were subject to a great number of racial migrations, with each new race displacing or pushing out the previous rulers, and it is possible that this is what happened with the nittaewo and the Veddahs.
Eberhart also records the theory that they may have been some unknown short-statured race of people, similar to the Negritos, the Semang of Malaysia, or the Andaman islanders.
According to Heuvelmans, Homo erectus no doubt once inhabited the rest of Asia before being pushed down into the Southeast by one of the waves of human invaders mentioned above.
Captain A. T. Rambukwella also theorised that the nittaewo could be a Sri Lankan species of the African Australopithecus, the females of which reached 4.3 ft (1.3 m).
However, the discovery of remains of Homo floresiensis on the island of Flores in Indonesia in 2004 has also lead to the belief that they could even be a similar species existing in Sri Lanka.