Question about strong emitters

[tamrin]

In some of my maps I have too strong emitters (high amt) that the creeper start to overflow from terrain and I want to avoid this effect for my future maps.  :D
Is there some way to stop this? Is there some limit which is recomended to not exceed?

[TLFP]

If your creeper levels exceed 500 then creeper can overflow onto void. The only way to stop this apart from using walls is the CRPL command setterrainoverride, found here.