Shortly after sunset one evening scores of thousands of ants descended upon me while supper was in progress. In the dim light afforded by the lamp I had not perceived their approach until I felt them around my feet. Upon looking about, I discovered to my astonishment that the floor, which had a covering of closely set bamboo stalks, was black with ants and that regiments of them were busily climbing up my bed. Coming in such immense numbers and unannounced, their appearance was startling. Outside the soil seemed to move. Twice before I had received visits from these ants but had prevented their entering the tent by pouring hot water over them. The pain caused by their bite is severe, although of short duration, and they are therefore feared by the Dayaks and Malays. By liberal application of hot water and burning paper on the ground we finally succeeded in driving the unwelcome visitors out of the tent; but new hordes were constantly arriving, and we battled for two hours before I could retire, carrying many bites as souvenirs. None were then in the tent and next day not a trace of them remained. The Chinese photographer had been there twenty minutes before the raid began and had not noticed even one ant. The attack began as suddenly as it ceased. My stay on the Kayan River had been interesting as well as profitable. Twice during that period requests had come from the government for Dayaks willing to join a Dutch enterprise operating in northern New Guinea, and the chances of my securing sufficient men on this river for my expedition were evidently gone. However, with the assistance of the government I felt sure there would be no difficulty in securing them from other rivers of Dutch Borneo, but I deemed it wise to begin my return trip. The river was now so swollen that it was difficult to effect a departure, and current report indicated that if the rain continued it might be necessary to wait a month before the rapids below could be passed. I had all my belongings packed in order to be ready to start whenever it was found advisable to do so. While waiting I went over to the kampong to kinematograph two dancing girls who the day before, owing to their bashfulness, had detained us so long that the light became inadequate. At last the river fell about a metre during the night, and the chief and his brother called on me early in the morning to suggest that our best plan would be to start in the middle of the day.