It must be spring. The grass is getting way out of hand, but it's too wet to mow. This happens every year.

Chickens on free range like short grass. Back in the Golden Age of scientific poultrykeeping (roughly 1910-1960), this sort of thing was researched. Chickens did best on grass that was 2" high. Once it reached 6" it became a barrier to foraging. If it gets even taller, the chickens are confined to a few paths through the tall grass.

Tall grass also shorts out electric fence and can conceal predators. A field that is kept short has a lot of succulent, green regrowth, and bright green grass is the only kind that provides any nutrition for chickens. This nutrtion, by the way, consists of more vitamins than you can shake a stick at, some protein, but no calories.

Rain, rain, go away!