Nursery Parent Notification Solution

Does anybody use some kind of technology system to alert parents of primary or nursery kids?

I was wondering because when kids in nursery need to go to the bathroom there needs to be a simple way to notify parents to come get their kids, this would prevent nursery workers from taking a kid to their parents and being alone with the kid, or leaving the nursery empty.

I'm just curious what others do to solve this situation since I'm guessing it's common

Thanks in advance!

We always had at least three adults in the nursery (often four: two couples). That way, one individual could leave to summon a parent without violating any 2-deep leadership rule. When needed, we always had volunteers from EQ or RS when we were shorthanded because someone was out.

Of course, you will need to sort out what works for your unit depending on the size of the nursery and number of available adults for callings.