Well you could be more specific which ones. the 2.4ghz and 5ghz leds blink when they're transmitting data. The power led blinks if the firmware is corrupt. Guest wifi blinks if sending/recieving data. USB led blinks when a usb device is trying to connect. Ethernet ports blink when sending/receiving data.
Page 13 of your manual goes over what the led lights mean. here's where to get it.
Are you having problems or just curious?