Good news: There is an inexpensive, fun, creative, hands-on activity that combines science and art and keeps your kids away from their screens. Bad news: It’s slime. And now it is in your couch ...

When I was a kid, there was a now-defunct children’s play place called Discovery Zone near the apartment complex where I lived. It was a little like a mashup between a school playground and Chuck E.

Probably because I am not a 7-year-old, I did not initially understand the appeal of slime. The stuff is everywhere now, oozing out of all corners of the internet. I’m told by friends who have ...