I’ve had a recent issue with my Android 4.4 phone causing a constant network activity and draining my battery like crazy. After searching over Internet I found that could be due to one of my devices on my local network (because of a packet broadcast). I disconnected everything, but no luck. Then I installed an app from the store to find which apps are using my battery, but it states it was Android System…
Some forum posts said that could be some ICMP traffic due to the phone trying to reach the Google servers, or something similar.
Finally I installed several applications to monitor my phone. The best one was « Network Log » that is able to show the trafic received/sent for each application. I found that one of my app might be the issue: I uninstalled it and the trafic stopped!
So I recommend this app to find out which app could be the reason of the bad network activity.