Congrats! I've got clones healing up right now too.
From what I've read it's either a sign things are great or a sign things are bad. If good its because the ecosystem provides enough for it to reproduce. If bad its because it's a survival technique.
I don't know how to trigger it but mine started after I started feeding it 2-3 times a week. Chopped tiger prawn...the guy at Costco made a priceless face when I asked for 6 prawns. "6 lbs?" "no, 6 total"...."ok". Lol