I don't use anything. I keep them in a tupperware container and when they get ready to cocoon they just do it on the sides of the container. once the cocoons are hard enough you can pull them off and put them in another container with no lid(they don't fly) and they can hatch right in there.
Yes I found they like to spin in the pockets of egg cartons I just cut them into strips and left the pockets in-tacked and lined around the container I grow them in
Now since I shared my knowledge I'll need some mulberry leaves or even better yet if you can get me a branch to sprout new roots woohoo haha
ok thanks guys. 2 have already started doing it on the sides but I thought I would need to make something out of chickenwire or similar.
there are quite a few mulberry trees around me but most of them have had their branches cut off up to about 10'. Apparently people are allergic to them so the city is trimming them back