My backyard is about 10 metres x 10 metres?garage down one side ,house on another and 2 other sides high fence,rough mowed grass etc inside and when i put the beardies out there they can`t get out,but when you go to find them you are sure that they have sometimes?They don`t like to be out in the open and re always on high alert for birds and can see the tinyest speck of a bird high up in the sky.It will most likely be burrowed into some weeds etc not far from where the cage was.The time I lost my one I left the garage door open and it went in there and out the other door and just a couple of metres around the corne under the mower,three days later?I would go for a dog to find it,and I know people who have found missing tortoises with them,Maf sniffer dogs would be the go if you could get in touch with them,they are under good control and will just find it too.