I've had the opposite experience in the past! I planted some mint seeds, and then it took over the yard! Thankfully, it's a problem for someone else now, as my family has moved on LOL!
What type of lighting are you keeping these slips in? South facing window? Grow lights?
South facing window. I had heard that, mint would take over but alas, no such luck here. It's supposed to keep ants and mice and mosquitoes away.
I had no idea about keeping ants, mice and mosquitoes away! Hot damn, looks like I'm going to start some mint! I wonder if it would fare OK in a container. I refuse to let it take over my new property!
I've planted mint in a pots and buried the pots. That keeps it contained. The roots are what go crazy.