He liked to sit and watch them and keep the kites away.

He said it was white man's knowledge (science ?).

Yes, the animals were pegged out alive on the ant-hills, and the professor would sit with his watch in his hand, counting the minutes until they ceased from writhing.

It was part of the duty of the ten to catch animals and bring them alive to him in camp for that purpose.

No, they did not know why he did it, except that it was white man's knowledge.