CABB OF CAPTIVE ANIMALS — WALKER 325 



wheat flour, 2 parts skimmed-milk powder, 1 part powdered dried 

 yeast, and 2 parts of standard wheat middlings. This should be 

 thoroughly mixed. When ready for use, it should be mixed with 

 equal parts of honey and glycerine until about the consistency of 

 wet sand.^ 



The adults, maggots, and pupae of the common housefly {Musca 

 domestica) and the bluebottle or blowfly {Calliphora sp.) are good 

 and convenient forms of food for a number of animals. They can 

 be caught and raised fairly easily. One method of capturing the 

 insects and of starting the cultures is to place in the open, where 

 flies can get to it, a conical or pyramidal screen wire cage with a 

 small hole in the top plugged with a cork or a piece of paper, and 

 with a door on the side that can readily be closed. This is usually 

 placed in a pan or tray in which is meat or fish to attract the flies, 

 and the door of the cage is left open. The flies enter the cage to lay 

 their eggs on the meat or fish. If one desires the adult flies at that time, 

 he closes the door and removes the flies by inverting a wide-mouth 

 bottle or screen wire bag over the opening in the top of the cage 

 after the stopper or paper is removed. Now, by tapping on the 

 sides of the cage, the flies can be induced to go upward into the 

 jar or screen wire container in which they can then be transported 

 to the cage containing the animal that is to be fed. The eggs are 

 permitted to hatch into maggots. These feed on the meat or fish, and 

 in this stage can be fed to animals, or they can be allowed to pupate 

 and permitted to hatch into adult flies, thus maintaining the cycle. 

 If there is a layer of sand or sawdust an inch or two in thickness on 

 the bottom of the pan on which the meat is placed, the maggots will 

 enter this to pupate. The pupae will hatch into adult flies in 6 to 

 15 days, depending on the temperature. However, by placing the 

 pupae in a refrigerator, hatching can be delayed indefinitely. The 

 pupae can be removed from the refrigerator from time to time in 

 such numbers as needed, and permitted to become warm, whereupon 

 they will hatch into flies that can be supplied to chameleons, aniles, 

 and such other creatures as require this food. Shrews and a few 

 other mammals, and many birds and some reptiles, will enjoy the 

 maggots and pupae when they might not take the flies. 



Cockroaches can often be readily obtained and are freely eaten by 

 many animals. Cultures can easily be maintained. 



Earthworms {Lumhricus) are excellent food for many animals, and 

 cultures can be kept in rich garden soil in almost any container that 

 will prevent the worms from escaping. Earthenware or wooden 

 containers are preferable to tin. The soil should be slightly moist 



* This formula was developed by Dr. Mykola H. Hydak and described by him in the 

 Ann. Ent. See. Amer., vol. 79, No. 14, pp. 581-588, December 1936. 



