Do you tip a pet sitter?

[divingbiker]

You people made me paranoid ...we have a lovely sitter and we've never tipped her. She charges $20 a visit though, so she's being pretty well compensated. I tip just about everyone else but it never occurred to me to tip her. Now I'm thinking maybe we should...

I think you're fine. I pay $20 a visit, too, and I think the pet sitters much prefer a regular customer (and regular income) to an occasional tip.