Repetitive opening of beak

[Jakico]

My buff Brahma chicken will open her beak real wide. She pulls her head in close and then extends her neck likes she’s about to crow. She doesn’t seem to be distressed when it’s happening. She will do this in several repetitions. She is almost 7 months and not laying yet. Is this behavior normal?

 

[EggSighted4Life]

Is she just burping?

 

[aart]

Probably adjusting her crop contents.
Video would help here.