Of large and small collections alike, though probably more for those of us who don't grow many carnivores (I spread my love over many types of plants!). This is particularly useful for those who cultivate indoors. I am an avid composter, but I am also very lazy and only head to the backyard to throw out my veggies once or twice a week. In the meantime, they pile up in a bag in my garage. I find that after a few days, there is a decent sized colony of fruit flies that have made a home in the bag. Sure the have wings, but they work just the same to feed carnivorous plants. So long as you don't keep the refuse in your home, the fruit flies won't be a problem after you've used them to feed. It's a free and very easy way to give live food to your plants.