G'day. Yup, they're "bearding" looks like. They may be keeping cool :mrgreen:, or given the size of your hive, they may be over-crowded and preparing to swarm. If you see any supersedure queen cells hanging off the frames, I'd expand immediately. I would expand to 10 frame hives with screened bottom board SHB trap bottom with a screened inner cover for better ventilation. I would also raise them up off the ground, just like your house, mate.