Yes, I actually raised over 700 Monarch "cats" at one time. I used the method of 2 liter bottles with the bottum cut out placed on 1 lb. margerine tubs with 3 holes drilled in the lids. The tubs had water in them and I placed sprigs of Butterfly Weed in the holes--put several "cats" on them, covered them with the 2 liter bottle, then put masking tape from the tub to the bottle to hold it on. I could start as many as 25 babies at one time in one bottle and as they grew would decrease the amount till there were only two in there. I had over 70 - 2 liter bottles going at one time with all the "cats" in them. Of course, these all had to be cleaned out each day.
During the height of all this I was only getting about 4 hrs. sleep each night---and I didn't have any help taking care of the "cats" or chrysalises etc. My husband would help me find the "cats" and help me find the plants for them to eat. I have about 30 Tuberosa Butterfly Weed plants in my yard plus about 50 t0 75 Tropical Butterfly Weed plants in my yard. This is where I found most of my "cats" and eggs. I only use these to feed the "cats" when I have to. I get most of the feed for them in the wild for as long as it lasts. During this time I was also doing Butterfly Presentations to schools, Clubs, Libraries, and presentations at my home.
Wherever I did a presentation I always had 6-8 Monarchs hatching while I was talking.
I don't raise the "cats" in the 2 liter bottles anymore. I learned to raise them in large totes--40 qt. clear storage containers. This is much easier.
I use 8 Oz. margerine tubs fixing them the same as the one lb. I could put as many as six tubs in a tote with as many as 20 to 24 cats in one tote. And it was much easier to clean and take care of them.
Of course, you have to cut out most of the top and hot glue screaning on the lid so they have ventilation.
This past spring I raised over 200 and now so far I'm raising about 250 "cats" and chrisalises. A Monarch just came through the yard today and left some more eggs, so this will continue till oct. I've been tagging the ones that have hatched and have tagged 8 wild ones too. Last year total I raised over 1,000.
Jeanine Shaffer, Monarch Way Station 381