howdy: i'm new at chickens, and very puzzled. today i was holding my 18 week old black australorp pullet, and noticed that her beak looked a little funny. i thought "cross-beak", then took a closer look. It's actually cracked! she shares her coop with three other pullets and a one roo, all the same age. roo is getting amorous, girls are very stand-offish. so here's my questions: how could a beak become damaged like this? how do i treat it? will it mend? thanks!