Where did you place them? Are they in an area that receives at least 6 hours of sun each day? They may have gotten some sort of disease. Ants on peonies is a good thing, I guess, since they're attracted to the sweetness of them. They don't hurt them. Did they bloom prior, this was 3 years ago, and they bloomed fine the other years? Maybe try giving them some fertilizer- there's a brand by Bayer- it's a three in one for roses and flowering plants. You only apply it a few times, maybe that will help, I do know peonies do not like to be transplanted, they may take awhile to recover from that move, so be patient with them. You can also go to the peony forum, those folks know alot too.
Good luck to you.

Last year's weather threw a bunch of specialty spring blooms into a tizzy. None of my shooting stars (dodecathion) bloomed either, and my iris were pathetic. Peonies are VERY heavy feeders and likely would benefit from a good load of a gentle manure about now to give them a boost for blooming this year.

-Marie

Peony are known for sulking after divide/move. However, they are also sensitive to depth of planting. Forming buds but not blooming is a sign they may be planted too deep. Make sure that during transplant the crown didn't get put down too far. If so, dig them up and reposition them.

You are not likely to lose these plants - they are very tough and very long lived.

What you most likely have is a blight called Botrytis which can be stopped by spraying the plant early in its growing season.. After spraying mine only once last year when it was about 6" tall I eliminated it and was able to have nice blooms. Be sure to clean up in the fall. HEre is a link for more info.
Good luck!
Lynn

Here is a link that might be useful: Peony Diseases

Thanks for all of the info! Can I still dig up my peonies this Spring or should I wait until Fall? They are between 5 and 10 inches tall right now.