I never leave my cats unattended for more than 24-36 hours. after that, I have someone stop in; longer than a few days; i hire a petsitter. it is extremely traumatic for some pets to be left without you. They have a routine, they are comfortable with it. Since you can't really explain to them when you'll be back; imagine YOU being left somewhere for 6 days without anyone telling YOU when they'd be back with food; water, whatever. Even if you had enough.... How would you know without being told that you weren't going to run out, that you weren't abandoned?