I reared 55 monarchs this summer with the help of this cage. I placed it with the vinyl viewing window as the bottom, layered with paper towels, for easy cleaning of all the frass. The cage is big enough to allow room for several soda cups filled with water and cut flower food with the milkweed stems stuffed through the straw holes. I kept the eggs and first/second instars in smaller cages and moved them to The Big Tent when they were nearing pupation. The cats hung up on the net ceiling and when the monarchs eclosed, the zippered flap hung down and kept them from flying out as I handled them. Love this cage!