In survival, chickens follow you when you are holding regular wheat seeds, but do not follow you if you have melon or pumpkin seeds. You can breed chickens with melon or pumpkin seeds, but they won't follow you.
Note 3
MCPE-9125
Chickens do not follow players holding breeding material other than wheat seeds
Resolved
Fixed
0
(Unassigned)
Confirmed
Phone - Android - Samsung Galaxy Note
5.0
0.10.4, 0.11.0, 0.11.0 Beta 14, 0.11.1, 0.12.1 Pre-release, , 0.12.1 Beta 12, 0.12.1 Beta 13, 0.12.1, 0.12.2, 0.12.3
0.13.0 Beta 1
Retrieved
Confirmed for 0.11.1 on iPhone 6 plus (iOS 8.4). Also occurs when the player wields beetroot seeds.