This is what happens when biologists start playing with electronics. To make this is more valid experiment, I would mount the telephones remotely, and use exte

This is what happens when biologists start playing with electronics. To make this is more valid experiment, I would mount the telephones remotely, and use external antenna in the hive, fed via coax from the remote telephones. Their control of a telephone in standby was not a good control. The standby telephone has it's power supply in a low current state to save battery power. This results in a couple of things. There is significantly less heat generated by a standby telephone than an active telephone. Bees respond to temperature. Modern electronics use switching power supplies. These switch currents through inductors at high frequency to step the battery voltage to the IC's operating voltage at high efficiency. You can often hear these switching supplies, as they cause the inductors to "sing", as the high frequency is demodulated down into the audible band by component imperfections. So, the bees may be responding to acoustic noise from the power supply. We have no idea what else is going on in these phones. is there a backlight on the LCD? If it's electroluminscent, that also can sometimes be heard, as it has it's own, much higher voltage supply. If it's LED, that will be generating heat. If the experiment is repeated, please use remote telephones with external antenna in the hive.