There are no simple answers really when it comes to some of those questions. Nutrition is a very complex issue due to the interplay of many of these different vitamins and minerals, and calcium is one of those that interacts with a lot of others. However, there are some key things to watch for. The one you always hear the most about is calcium and phosphorous. One of the reasons for this is that calcium and phosphorous love to bind together in the intestine, which makes them both pretty useless. Not a problem with the phosphorous, as there is normally a large excess of this in the diet of insectivores anyway. However, it is a problem with calcium and can lead to a deficiency as a result of a high phosphorous diet. And insects we raise in captivity are very high in phosphorous. Therefore, though reptiles only really need about a 1.4:1 Ca ratio in their diet, it is usually recommended to err on the side of caution and go for a 2:1 ratio. There is also a feedback loop between calcium, phosphorous and a hormone produced by the parathyroid, but that should really only come into play dietarily when the excretory organs are compromised. There are other interactions that are important to remember though. Oxalates, or oxalic acids, are one you often hear about now, and are found plentifully in many vegetables, specifically the dark leafy kind. Spinach is recommended less and less due to the presence of lots of oxalates, as are kale and collard greens. These have similar properties as phosphorous in that they join with calcium to form calcium oxalate. This is not absorbed in the intestine, but rather excreted with the wastes. So in essence with both of these additions of phosphorous and oxalates, you can have a very high calcium diet that does not result in a good calcium absorption rate. There are other influences on this as well, magnesium, copper and fat all have an effect on calcium in the body, as does serum Vit D, temperature, and pH levels too. Those are a little more complex and not quite as monumental in insectivores though. These things above are why people are always talking about giving as much variety as possible. Some vegetables have moderate oxalate levels or reasonable goitrogens, while others are high or low, so giving a good variety will alleviate many shortcomings and mistakes. As for protein, the quantity may be more of an issue than the source. Insects like crickets and roaches are adapted to low protein environments generally and get nearly all of their protein requirements from plant sources. They are generally best on a diet of around 15-18% protein. With dog and cat food, for instance, you are looking at around 30-40% protein. Proteins are big chunky things that take a lot to metabolize and excrete. Too much of these proteins in the diet means the digestive and excretory systems are working overtime. As for the source of the protein, it seems to be a little less important. There are some slight differences, such as animal proteins leading to a more acidic pH balance (which can slightly alter things like serum calcium levels) but those seem to be fairly minor variances. You will probably find that many insects will choose animal sources over plant ones when you feed various diets. However, this is not due to the plant or animal proteins themselves and instead has to do with fat. One of the final steps in dog and cat food processing is to spray the 'bits' in a nice coating of fat. This makes what is a pretty gross paste into a more appealing tasting food for your dog or cat (theres a reason they snarf down the 'wet' food and usually leave some dry in the bowl). The same reason that butter and bacon taste good to us is why that fat in the dog and cat food 'tastes' good to the insects. Fat has a lot of calories, and in the competition of natural selection, animals in the wild do not turn down a lot of calories when they are available. In the high competition of the natural world its not usually any problem as food scarcity is regular. In the unnatural conditions of humans and the animals we keep, its a problem for reptile and people alike. CRRL, I guess I dont understand how the difference in humidity would be caused by the different dry mixes we each talked about. That could be one reason for using water crystals versus fresh vegetables, but is more an enclosure question than one of nutrition. As for the humidity problem with enclosures, I wonder if installing a small computer fan into the lid of the cricket enclosure would solve the problem. Just a thought, but they are cheap, small and use very little electricity. Like Dragoness, I have a fan that blows over the top of my roach enclosures in the summertime as it gets so humid here. Without it I will often get condensation as well. The enclosure I have my crickets in is open topped, so no humidity issues there, although I know this is not convenient for most people.