ANY-maze can detect times when the animal is immobile and times when it is freezing, but what’s the difference – they sound the same?
Immobility is actually something you define by saying how immobile an animal needs to be. Typically it is used to detect when the animal has stopped moving from place to place – for example, it might still be grooming but it’s not altering its location. Alternatively you could specify that the animal has to be even less mobile, so not grooming, but perhaps still able to move its head a little or twitch its tail.
Freezing detection, on the other hand, is specifically used to detect when an exhibits freezing behaviour, defined as ‘suppression of all movement except that required for respiration’.