I think I may be a groupie.

I'm not quite sure how it happened or when, but I realized this week that I am part of a strange underground that exists beneath the seemingly normal day-to-day humdrum of motherhood.

My band of choice? Rocknoceros.

This motley crew of middle-aged men sings ridiculous songs to toddlers as they masquerade behind their characters of Coach Cotton, too-cool drummer Boogie Woogie Bennie and Williebob, the overall-clad farmer. Yes, each is more dignified than the last. If you haven't seen this group, try to imagine the Wiggles on a shoestring budget.

I sat in the audience at my first Rocknoceros concert several weeks ago, laughing at all the other moms who seemed intimately aware of all the comings and goings of the group. Some kids sported Rocknoceros T-shirts. Some moms waved hello to the band members and said it had been so long since the last concert and that they were so excited for the new "Pink!" album to drop.

As the music started, a girl who couldn't have been older than 7 stood up and shrieked with joy that the "American States" song was next. Next to her, a hip-shaking toddler tried to climb up on the stage to get just one touch of her beloved Boogie Woogie Bennie.

This is weird, I thought. I half expected one of the moms to lift up her shirt revealing a tattoo of Williebob while screaming, "We love you, Rocknoceros."

But when my 2-year-old daughter started dancing and shaking and laughing uncontrollably at the silly songs, I was hooked. Now weeks later, I already have two Rocknoceros concerts scheduled on my calendar and I have visited their fan Web site more than once.

I am not proud of this, but there it is: My name is Erin Stewart, and I am a groupie of a kiddy rock band.

It's just one more symptom of a much larger phenomenon in the life of most moms. You see, being groupies to rockers for tots is just one of the many ways in which moms are part of a strange culture that is inexplicable to outsiders.

Let's look at some of these highly unusual behaviors included in the oddity of motherhood.

1. We have strange dating rituals — That's right. It's time to fess up, moms. Our husbands may not know it, but we have intense and complicated relationships while they are at work. We date other moms. Well, to be totally accurate, we playdate them.

We have dating partners with whom we do weekly or monthly activities under the guise of letting our children play together. It's a sad day when you see your co-playdater at the park with (gasp) another mom. Oh sure, you'll act like you don't care and you'll casually ask, "Oh, was that you and Betty at the park yesterday?" But it cuts deep.