How do you know when to call the parents? When you are babysitting and the parents are trying to enjoy adult time is, rule of thumb is don't call them. However, there are a few instances in which you must call the parents, namely if you experience a babysitting emergency (severe injury or severe damage to the home), need to call poison control, or occasionally if the children are überwild and you cannot get control.
Injuries This is a tricky topic, because kids get hurt all the time. They'll sometimes embellish the extent of their pain, too, for attention. However, you've likely seen the difference in a typical bruise or scrape versus something that requires stitches or a visit to the emergency room. The tough ones are the in-between injuries. These are the ones that are fairly serious but don't necessarily require a hospital visit. (First-degree burn, cut in a strange place, like above the eye, etc.) For these and worse, call the parents. Leave a calm message if they don't answer, letting them know that the child was hurt—where on his body, and how/where in the house or outside that it took place. If you think it's necessary, call the child's doctor. You may get the voice messaging service, but they can contact the doctor on call. Of course if the injury is bad enough, or you aren't sure, go to the emergency room. This would be considered a babysitting emergency, and in this case, you'll know when to call the parents.
Damage to the Home It's amazing what will happen when the parents aren't home. But remember, they know their children, and they've likely experienced the same or similar catastrophes as what happens when they're away. Maybe it's a plumbing emergency. Perhaps a body part or hard toy breaks through the drywall. A ball crashes through a window. Computers break. If something huge and/or structural breaks or is damaged, go ahead and call the parents so they'll know ahead of time. If a dish breaks? Just let the parents know when they return. In the case of a plumbing emergency, call a plumber of course, but still call the parents to let them know. They may know what the problem is or have a particular plumber they'd like for you to use.
Out-of-Control Kids Once in a while you'll run across a situation you simply don't know how to handle. No amount of disciplining, yelling, threatening, or other means of psychological reasoning can stop the bad behavior or "wildness." Before a babysitting emergency or something unfortunate happens, go ahead and call the parents. Maybe it was your fault for letting the energy escalade—now's not the time to worry about looking stupid or being at-fault. It's time to ensure the safety of the situation for the children and yourself. And by "wild" that means screaming for long periods of time, running through the home, hitting or kicking themselves or you, jumping on furniture and/or countertops, taking off clothes (when not bath time), using the phone inappropriately, being consistently belligerent, "running away" or hiding where you cannot find them, etc. You know when to call the parents if these behaviors don't stop. It won't be a fun conversation, but it may be necessary. Then you can choose whether you'll sit for those children again.
The Surprise Fix-It Guy When someone shows up at the house unexpected, the kids usually get excited, the dog barks, and you may go into alert mode. More than likely this person is legit, and the parents just forgot to mention that they were coming, but wouldn't you rather be safe than sorry? Call the parents before letting the person in. If it's a family member or friend of the parents, that's different, and the kids can tell you. But even if the kids "know" the fix-it person, give the parents a call to verify. If you can't reach the parents, simply ask the person if they can reschedule with the owners of the home.
Uncomfortable Situations Ah, yes. The unexpected, often unheard-of comment or action from the child. The type of thing for which no amount of babysitting—and sometimes even parenting—can prepare you. This can include anything from children who appear to have psychological disorders the parents didn't mention, to children playing with their private parts and asking about yours, to a child musing uncanny thoughts that make you question what he's seen or heard elsewhere. This is a tricky topic, because it can be embarrassing to tell a parent that a child has said or done something that makes you uncomfortable, but it's always your best bet to let the parent know. Sometimes the parent will (for example) relate the incident to a movie the child watched with older cousins, or "remember" to tell you that the child is seeing a psychiatrist due to some childhood trauma. Sometimes they may ignore the fact that you told them, or defend the child. What you DON'T want to happen is for the child in any way to implicate you, if you try to solve the incident yourself. Don't interrupt the parents' evening, but do let the parents know how you handled it, and decide if you want to continue babysitting for the family.
This advice is based on years of experience—however, you know best when to call the parents. Try not to bother them unless absolutely necessary.