Mint is perenual, invasive, and impossible to get rid of it once you plant it, cause it propagates via roots. It doesn't stay where you plant it, pops up everywhere.
If you don't want it taking over your garden, some people do in certain instances. You may want to try and dig it up and transplant it to a pot. IF you do this make SURE you get all the root, dig pretty far around it.
Basically agree with above. The reason why people caution against mint is given decent conditions it can be so aggressive/ invasive, take over your yard. I have some planted in the ground in dry shade, poor clay/rock soi. Given that, it still spreads, but not as rampantly and I can keep up by pulling it.
If yours is in better conditions than mine and if you don't want a yard full of mint, then gixx is right, better to dig it out and put in containers.