grass in poo

First time user, bare with me here, you can answer whichever you like… 1. I’ve got 3 chicks, and I don’t know what their breeds are. Leghorns? Orpington? The two bigger ones (1&2) are supposedly 6 weeks and the 3rd is 5 weeks. Might be stupidly obvious, but I also want to know which is male...