How Not to Lose Your Child at Crowded Events

This is Corvidae.  She's almost three.  As a toddler, she can navigate crowded areas easily and faster than an adult because she doesn't mind stepping into other people's space bubbles nor does she mind colliding with someone's legs at full speed.  At crowded events full of shiny objects fascinating to toddlers, this speed is a liability.  She can literally disappear into a crowd in the blink of an eye.  

At the 2012 San Mateo Maker Faire, I wrote my phone number on the back of her shirt, so when she did get away, the nice people running a booth about robots could give me a call.  Her shirt was a great conversation starter.  At every single place we stopped, another parent commented on her shirt and told me about the time they lost their kid.