I was camping and jumped into a sleeping bag, got all zipped in only to find I had a mouse in it. My shrieks were heard for miles, I'm sure.
Greg ~ the iris are similar to semps in some ways. After a rhizome blooms it will never bloom again so you count on the new baby rhizomes to bloom the following year. If your clump gets old you could have a bunch of the non blooming rhizomes in the middle that need removed.
Cheers!