You can get adult insects looking for some place to lay eggs that will become more of those insects in any compost pile, especially if it is somewhat dark like in a closed container. The adults would not be a problem, but the larva that might hatch from the eggs could be and if they are present it is an indication that your material is simply too wet, since these larva need a fairly moist environment to hatch and grow. Many people, that mistook the Black Soldier Fly for the Black Soldier Beetle, once maintained that these larva aided in digesting the material you are making into compost, but since many of them turn into adult insects that can be carriers of disease pathogens it is not a good idea to encourage them, and that material being too wet can inhibit the activity of the thermophilic bacteria you want making your compost.

It is bacteria (microscopic critters) that digest the material you put into compost and they can go through several stages while digesting your compost. The presence of insects, Pill or Sow Bugs, maggots, etc, is an indication that the compost probably is too wet because all of those wee critters need a fairly moist environment to exist, an environment that can exclude the oxygen the aerobic bacteria that shoulkd be at work need to function.

Black Soldier Fly Larvae are somewhat common in compost piles and its not because they are too wet. Compost is supposed to be moist, but not too damp, and it contains decaying organic material. Its a perfect habitat for BSFL. The larvae are not bad for the compost and they are not bad for your plants. They are really gross to look at and I would prefer not to see them. I keep my pile on the dry side... it has lots of dry straw and I rarely add any additional moisture and I still get the occaisonal BSFL mass of goo. Eventually they will hatch and fly away. I wouldn't worry about them and I wouldn't look at them either. You mentioned not seeing any earth worms. That is not surprising. Earthworms don't really like a warm active pile, they prefer the pile when its cooler and closer to finished compost. I wouldn't worry about lack of worms either. Here is a link that might be useful: Black Soldier Fly larvae

Bugs are good. Those particular bugs are probably around because of the food source your compost pile provides. If you want to get rid of them, try covering your pile with more browns like dead leaves. Secrets? There aren't any, really. I've found a common mistake many beginner composters make is to not use enough browns in their pile. Kitchen scraps are green, and will break down into practically nothing. So go find yourself some leaves; the more the better. And then, wet them down and stack and pile them up. The rest is up to you. Leave them there and do nothing, and it should break down in a couple of years. Turn it and water it whenever necessary, and you'll make compost quicker. Here is a link that might be useful: Here is more info