Get yourselves a Phiomia as well! Feed it stimberries and you'll have plenty of medium feces to throw in the dung beetle. Fill it up, and come back and watch more fertilizer than you can imagine. I'll never use compost bins again!
On the island, I think the easiest place to find them is in the lower south cave. Go in with a longneck or a shotgun, turn left at the first intersection, kill the boas and spiders I. The first chamber, near the end of it there’s usually 1-3 beetles. Tame, and carry back to base w/ Petra. Easy fertilizer.
Turns human and dino poop into oil and fertilizer. Make sure the dung beetle is on wander and has plenty of poop, it takes about 15 min per cycle.
1 Human poop becomes 1 fertilizer and 2 oil
2 Small poops become 1 fertilizer and 2 oil
1 Medium poop becomes 2 fertilizer and 4 oil
1 Large poop becomes 3 fertilizer and 6 oil
1 massive poop becomes 16 Fertilizer and 14 oil.
Every cycle can do one "transaction" for each type of poop for a maximum of 7 fertilizer and 14 oil without massive poop or 23 fertilizer and 28 oil with a massive poop.