When my air conditioning pops on (it is on automatic) there is a clicking noise above my toddler's bedroom that lasts for at least 10 seconds. It is getting longer each time. It is loud enough that it wakes him up sometimes if he is sleeping. Is there anything I can do?

Need to isolate the sound first...
Could be the fan, could be switches and relays, could be the refridgerant pies, coule be check valves...
Once you know where the sound if from than we can help you as to what to do about it.