While 10pm is a bit late to call, I actually have the opposite guidelines...I don't answer the phone during daycare hours unless it is naptime. I ask parents to call at naptime or in evening or on weekends. I cannot concentrate on talking on the phone while caring for the kids and the only time I tried to do that, wouldn't you know...a spider ran across the floor and a toddler went toward it and was about to pick it up...I shrieked and nearly dropped the phone...then didn't know how to explain it as I didn't want to person to think my daycare is infested with spiders I never again took a call during daycare hours unless the kids were sleeping (by the way, the parent never called back...I wonder why...LOL).