Why do dogs run away even from loving pet owners?

Dogs are like two year old children. They can't resist the impulse to take off running after whatever scent or motion catches their senses. Curiosity takes over and the next thing they know is some other scent grabs their attention... And on they go until they are completely lost.

I have 2 dingbats that are 9 years old and will charge the door and chase anything that moves until I can run them down. 3 others will  go out but not leave the porch. Then the other 3 run out the dog door to the back yard and have their fun running up and down barking at the escapees.

They are FUR BABIES and have that mentality.

I guess some dogs just love to run free when they can. I used to have a Brittany Spaniel that was dearly loved by the whole family but if the door was slightly opened ? Out he would go ! The kids would chase and catch him after an hour or so. The Basset I have now, when he was younger would run off also but after a year or so, he got used to his home and the last time he got out and I didn't know it, he sat at the front door and howled to get in. Just some dogs love to run free when they can and some don't. Best I can do ! :)