Thanks flux lizard. I definitely have fireflys. I'm not sure what to do! Make it out of hardwood cloth and cover it with screen? Not let them out after dusk? It's frustrating because I want to give them natural sun but am afraid of situations like yours.
Maybe- the dragons were actually eating the fireflies during the day- they crawled in I suppose at night, but the dragons were sleeping then. During the day I'd go by and find one dragon dead, then another a little while later and so on! It was terrible. So, unless you check carefully for fireflies every morning, I think just having a day cage is no insurance unless it comes into the house with the lizard at night.
My solution was to switch mostly to reptariums, and I've had great luck there.
I live in the country, I've seen possums, cats, skunks, dogs, rats, some kind of small hawk (don't know what it is- only about a foot high, sits on our deck and cries, and nests in a tree in our yard), coyotes, and even a bobcat once in our yard, and none have ever shown any interest in the lizards. I keep the reptariums on low rustic tables. I've seen dogs and coyotes walk right between the rows without a glance at the cages.
I have had 3 problems with predators-
1- a raccoon once tore into a metal screened cage in the old days that I had sitting near the ground. He ate a bunch (entire clutch- must have been a few dozen at least) of several week old dilepis that I had bred and hatched, and left me a big poop in the cage before leaving- I took the poop to the university extension service and had him identified as a raccoon. I started using tables after that and never had another racoon problem.
2- Not so much predator, but I did have mice once get into my lizard building before I knew what was going on. I knew I had a couple out there, but was inexperienced with mice and did not know the damage they could do. Within weeks I knew they had brought their friends and family with them! They cut holes into about 50 reptariums to steal food pellets from bearded dragons before I realised I had a problem one winter. I had to patch a lot of reptariums because of those mice and I keep mouse poison out for them to find ever since! I do have mice and some kind of short tailed rat that live wild in the fields around here and have seen them in the yard, but they have never bothered the lizards out in the yard.
3- a little kid who was a terror lived in a rented house about 100 yards away. Think 6 years old or so. His father was in prison. He had one of those little cars that little kids can drive that runs on a big battery. He flattened one of my nieghbors 40' x 20' garden completely with it. LOL. Anyway, one evening I saw him running out of the yard from under a row of trees where I kept my monkey tailed skinks. I didn't think much of it, and told him to come ask me if he wanted to look at the lizards and we would look at them together, but that was the only time I wanted him in the yard (because of his previous crime wave in the neighbor's garden - only 6 year old I know who had the police called on him!). I didn't think much more about it but the next day I found that he had returned later that evening and he opened and released several corucia including a couple of babies that I had produced. And that was the end of a nice group of corucia for me- this was shortly after they stopped coming into the country so there was no hope of finding more that I could afford, and although I spent many nights that summer with a flashlight searching the woods near the cages, I never found any.
So there are my tales of wo. Keep in mind these 3 and the fireflies are the only cage problems I've had after starting outdoor housing in the summers in the mid 90s, and out of hundreds (thousands if you count offspring kept outdoors until sold) of lizards. So odds are pretty much on your side, but if I saw a hawk bouncing up and down on one of my cages, for sure I'd be out there adding hardware cloth at least to the top and sides...