Find My iPhone/iPod: Does offline mean no WiFi, or can it mean asleep? My daughter lost her iPod. I do not believe it was stolen. She has tried the "find my iPhone" app, and it tells her the iPod is offline. She last used it about 27 hours ago.  The volume is turned off, but the iPod was not. It would likely be "asleep". Does offline mean for sure that it is away from WiFi signal, or could it means asleep?

I need to narrow down a search. It could have fallen out of her pocket on the yard - so away from WiFi (too far from the router) or it could be in her friend's house, in which case it still has WiFi. If it hasn't been used in several hours, will it be asleep such that it will not register "online" even if close enough to WiFi?
It means that the Find My iPhone service cannot contact the iPod. This could be because it's turned off, or because it's out of range of a known Wi-Fi router. If it's asleep, it will still register on Find My iPhone, so it's either run out of battery or not able to get onto Wi-Fi.