Slimes are an incredibly useful mob in Minecraft if you can find them. You can use them to make items such as sticky pistons, and other cool stuff. But to actually locate a slime you must think like a slime. Not really but they are quite difficult to locate but it’s not impossible.
Where Do Slimes Spawn?
Slimes spawn in the Overworld but only in certain “slime chunks” which occur below layer 40. Slimes are also prone to spawn in the swamp biome between layers 50 and 70 but the light level has to be 7 or less. Otherwise, Slimes spawning is not dependent on light levels. Another interesting fact about Slimes is they spawn more frequently in swamps during a full moon and never during a new moon.
More Spawn Requirements
This is not important to locating them but there are some interesting facets to how slimes spawn. Slimes require two vertical transparent blocks (which includes air, signs, and torches). This means, in theory, there is an ability to build a spawn trap for them. But the spawned space has to be clear of liquids and of solid obstructions. Big slimes require a 3×2½×3 space to spawn, medium slimes require a 3×2×3 space, and small slimes require a 1×2×1 space (or 1×1×1 if the upper block is not opaque).
That’s all there is to it now you can go out and hunt slimes your best chances are to go to a swamp biome during a full moon and farm as many of them as you can! You could also try to set up a slime farm which would be even more impressive!