@learycow ? one of our experienced Muscovy hatchers.Ok,so I'm a newbie but I red somewhere that an experienced muscovy Hatcher experienced "goo" with hatches, and it's apparently too high humidity during hatching. She recommended basically leaving the incubator at 65% , and only upping if the first to hatch out is having trouble. I know this is a late response, but thought it might be helpful to somebody.
Welcome to BYC @rookhomestead