I assume grub worms in my compost bin are okay, since they must be helping to break things down even more quickly, but just want to make sure.
Here's a picture of a big one I found yesterday.
The ingredients that go into our compost are about 50% leaves and grass cuttings, 30% vegetable and fruit trimmings and about 20% coffee grounds.
We occasionally get a lot of figeater beetles, too. I first see these as small, maggot-like larva throughout the compost, then after they mature they coming buzzing out of the compost and seem to be moving into new homes in the ground under the nearby tall grasses and groundcovers. They don't appear to be doing any damage to all that wild stuff.