They are pretty good escape artists. Somebody in another post said her's just went for a long, dry carpet walk
I have some black plastic netting that I use to cover mine so my Scissortail Dartfish/Gobies don't follow my Tilefish for a short flight. If you need it, I'm in Surrey on Thursday afternoon again. PM me if you want some. You can make a frame out of light wood & zap strap in on for a cover. Holes are 2 cm by 2 cm.