What did Fossey note when it came to the way the babies played with Uncle Bert? What unusual activity did the group do?

Fossey watched one day as Digit flopped into the lap of Uncle Bert, who tickled him with flowers. The youngsters of the group often "giggle" or "chuckle" when tickled, much as a human child would. One day Uncle Bert took the five infants of the group on a complicated "dance", which seemed to Fossey almost like a square dance, with the gorillas using small trees as partners.