There are many options for doing carnivore. I'll list both the easy and not so easy methods. Easy method 1, save scumming for pacu. Easy method 2, save scumming for shove voles, ranch them off dirt, block their movements with obsidian/pneumatic doors/1 tile-nowhere to jump to. Harder, but doable methods are shove vole hunting on the surface. It becomes a race to get there, but if you like to play on larger maps like neon eden then this method is much more difficult. The other method is ranching.