Atmega168 power down

I have a multi pir nrf24l01 setup on atmega168 on 4 Aaa batteries. Everything works fine. Everything I tried for power saving has failed. Powerdown, low-power, necroleptic. It seems to freeze transmit (pir is wired to battery)..any ideas? Should powerdown, sleep be in a particular place in void loop?

transmitter.ino (1.24 KB)

Got it! Works great.4 pit detectors, dusk til dawn power. Around 6mA in standby.