Yes, this is common with certain varieties of sweet corn under some conditions. I have 2 plantings side by side of the same variety and the first planting has a lot of these suckers or tillers. The later planting has only as few. They likely will not produce ears and opinion is divided whether they sap or help the main stalks.

I always leave the tillers.

Thanks for your reply. I think that your right about not making any ears. I have enough to run a trial, I cut some out and leave some to grow to maturity. if your interested I'll let you know the results. By the way, I didn't know that they had an official name, tillers. Never too old to learn.