Rhiannon tells me that the kid she nannies used to collect disposable latex gloves.

This started when he was around two.

He preferred the blue glubs but the kinda yellow glubs were also acceptable.

Hed wear them around and then stash them in his pockets, in drawers and in his play kitchen.

It was so gross, honestly, Rhiannon says of the sweaty, sticky things.

Members of theOffspring Facebook grouprevealed their own kids obsessive collections.

There were the common onesrocks, seashells, stuffed animals.

And then there were more obscure interests.

Another shared that her son collected garage door openers.

(He wants be a mechanical engineer, she writes.)

I think we all have memories of our childhood collectionsin the third grade, I collected eraser dust.

Lifehacker managing editor Virginia Smith collected hotel toiletries.

Our health editor Beth Skwarecki had a folder to keep her pennies, with a slot for every year.

To adults, these items dont spark much joy.

But for kids, collecting things has a lot of benefits.

By grouping and classifying objects, children are building cognitive functions.

This is a key mathematical skill that is essential for scientific thinking.

Kids often become hungry for knowledge about the item they are collecting, andthats a good thing.

Marketerslovethat kids like to collect things.Toys have long been invented around this fact.

(My husband remembers his Garbage Pail Kids collection fondly.)

But there has been a recent explosion in the collectibles market, spawning L.O.L.

dolls, Hatchimals and Pikmi Pops (if youve never heard these words before, be thankful).

AnAtlantic piecereports that marketers are convincing kids toys are about collecting, not about play.

Your kids collection shouldnt cause stress for the other members of your household.

That is, if you’ve got the option to.

Writes one mom named Kimberly: I found my sons booger collection a few weeks ago.