Strange ...

Making tea tonight and I noticed Sprout with his nose against the door casing. I called him and he ignored me, I said 'mmmm whats this' which sent tilly leaping about but Sprout stayed rooted to the spot. K was home and in the back garden. G at work j and E upstairs doing homework. So no reason for him to have heard anyone or anything. After about 3 minutes he moved and carried on as normal.... Strange dog...