Again, it has happened it many worlds over several years in several different versions of different modpacks/MC. Mostly in singleplayer. There is no Chicken trophies anywhere, it is just something that randomly happens in some locations once I build up my bases. In the present situation there are no mobs, hostile or neutral, anywhere in 100 blocks radius in all directions. The only thing capable of making sounds that I am aware of is myself and TiCo Drawbridges and neither of those sound like chickens. I can over time find a location that the volume of the sound is the highest, but the direction of the sound will still seem to be random and there is nothing notable in that location.