Sleep with One Eye Open

Since moving in Jackson has spent most of the day outside, coming in mid afternoon and through the evening except of course for a potty outing. He has claimed the yard as his property and does not allow intruders of any kind. We usually have to kennel him (he has a huge fenced enclosure I call a kennel) if anyone is in the yard. He allows Maggie and Janet in the yard but we do have to kennel or bring him inside first. Maggie loves to chase the squirrels and Jackson seems to know when it's time for her to come out - he goes in his kennel area and lays down. Maggie usually chases them for about 30 minutes -they don't seem to threatened by her (only 12 lbs).  One afternoon I noticed the yard was FULL of squirrels and black birds which was odd because Jackson usually doesn't tolerate that - where was he? I went out and he was sound asleep, snoring at the top of his lungs - too funny. Sounding like an old man who was a heavy smoker.  We were both on the screened porch and out of the corner of my eye I saw something move - it was a squirrel. It had come through the screen and was trying to get to the bird seed. I backed up into the house. The bag rustled - Jackson opened one eye, then the other just laying there waiting for the squirrel to get inside the bag. Once that happened Jackson slowly stood. After a few seconds he ran to the bag, grabbed it and drug it outside shaking it over and over again - then he tossed it into a large tree trunk out flew the squirrel which appeared shaken but ran off. Jackson went back to sleep probably with one eye open.