What do ''hens have pecking order'' means?

Mrs. hale (resentfully). i don't know as there's anything so strange, our takin' up our time with little things while wewaiting for them to get the evidence. (she sits down at the big table, smoothing out a block with decision.) i don't seeanything to laugh about.a possible disadvantage to hearing this scene, as opposed to reading it silently, is that mrs. hale may not