Daphnia can be grown outdoors in tubs of green water, as can mozzie larvae and cyclops.
Gammaris will live outdoors in green water too but they feed on rotting plant matter so you have to feed them on lettuce leaves.
Microworms are best grown in 2litre icecream buckets containing a thin layer of cooked oatmeal, sprinkled with bakers yeast. New cultures need to be made up every few weeks because they start to go off after a couple of weeks.
Grindle and white worms can be kept in containers of peat or fertiliser free potting mix and fed on dry baby cereal. You have a piece of glass on the peat and the worms gather on the underside of it. You lift the glass out and rinse the worms off into the tank.
Wingless Fruit flies can be cultured in 2litre plastic bottles. They are available from most universities.
Tadpoles are a good food and will appear in most ponds during the warmer months