So you think you trust your nanny? Well, after watching her with your precious little one at the park, the library, and the museum, I can tell you I might think twice before leaving my kid with her.

Most parents I know seem to adore their nannies. They rave about how much their children love their sitter. When the time comes to send the child to preschool, moms go all out to find new employment for the beloved nanny. But it seems like some parents just aren’t aware of what goes on after they leave the house.

There’s a reason nanny cams and websites like I Saw Your Nanny exist. When you hire a near stranger to watch your children — even if you believe you’ve vetted her thoroughly — you simply can’t know what goes on in your absence.

As a mostly stay-at-home mom who bounces around from library story times to aquarium outings to leisurely afternoons at the local playgrounds, I’m surrounded by nannies. Sometimes I witness them doting on your children, just as a mother would. Sometimes I see them lovingly and appropriately disciplining your kids, just as you would hope they would. But I also see where they misstep.

Oftentimes these less-than-stellar behaviors are somewhat innocuous. The nanny-on-the-phone situation is incredibly common — and maybe not all that different from what a parent would do. She mostly pays attention when your child really needs it, but that eternally long phone conversation sure seems to take precedence. The nanny clan is also prevalent, where groups of nannies are much more interested in socializing with each other than in tending to their kids. One nanny I’ve seen happily passes off babysitting duties to the children’s librarians while she catches up on the latest People Magazine.

But then there are the situations that — to me — simply aren’t acceptable. Like the nanny who parks herself on the playground bench every afternoon, absorbed in her daily crossword puzzle, while your little one wanders solo and bored, calling out for help and attention without acknowledgement. (This nanny also wears heels every day, making it impossible for her to ever actually play with your child, who happens to occasionally need a hand at the top of the climbing structure.)

And then there’s the nanny who has no problem leaving your child crying in the stroller at the splash pad while she turns to her phone, exasperated and annoyed. And this goes on for about 20 minutes.

And it’s not a one-time occurrence. I nannied part-time during grad school, and the children confided in me that their regular nanny took naps on their couch while they watched cartoons — and this was a supposed screen-free family.

I’m not a perfect parent — I’ll be the first to admit that. I’ve been known to stand on the sidelines, immersed in a phone call and not realizing that my child wanted to be lifted onto the swings. But when I’m paying someone to watch my child, she’s an employee. This means when she’s on the clock, the child is her number one priority. And I expect her to follow my general parenting and discipline philosophies. When my child cries, for example, I see this as an opportunity to get to the root of a problem; it’s not the time to ignore him and hope the issue disappears.

I’m betting you have these expectations, too. But whether you think your nanny is the absolute best or you’re curious about the kind of care she gives your child, it may be worth taking a closer look.

For some, a nanny cam might be the answer — there are definitely pros and cons to taking this route.

Others may take it to the extremes by having their nanny followed.

I’m fortunate to be able to do all my work from home, so I’m often able to overhear some of our babysitter’s interactions with my son. (It’s SO reassuring to hear him giggling and laughing with her, and it’s also nice to be able to listen in as she masterfully handles the occasional obstinance or tantrum.)

It can be helpful to ask around. I loved hearing a glowing report of our babysitter — unsolicited — from an acquaintance at a local playgroup. You likely know where your nanny takes your child (and if you don’t, you should!), so there’s no harm in asking the local children’s librarian or playgroup facilitator or other moms who cross paths with your kids during the day.

And don’t underestimate the power of references. Ask specific questions to your nanny’s previous employers to determine whether she’s a good fit for your family. If there are gaps in her resume or if she’s not forthcoming about references, it may be that there are families she doesn’t want you to know about!