I had a hamster once who was missing for 6 weeks in the middle of the winter! I couldn't find it anywhere. So what I did was this: Next to his cage I placed food and water and hay and pieces of fabric and left it there. I also left all inside doors open. Every morning when I woke up, the food and hay and fabric was gone - so I knew that my hamster was still alive and started making a nest somewhere (it was winter, so a warm nest was very important because Hamsters originally lived in the desert!).
One day I happened to get up very early, switched on the light and saw my hamster sitting in the middle of the food I provided the day before. I got up and was able to pick him up.
Hamsters are most active at dawn and dusk - so they would normally come in the late evening or very early morning. Since we are all awake at late evenings, it is likely that a hamster would roam the place in the very early morning hours.
One day I happened to get up very early, switched on the light and saw my hamster sitting in the middle of the food I provided the day before. I got up and was able to pick him up.
Hamsters are most active at dawn and dusk - so they would normally come in the late evening or very early morning. Since we are all awake at late evenings, it is likely that a hamster would roam the place in the very early morning hours.