(However, the mirror test has faced criticism for its ability to measure self-awareness and can produce false negatives in ... ink on their heads via a mirror reflection,” study co-author ...

But the new findings suggest more species may be able to discern their reflections ... rate of false negatives, according to the new study. Additionally, training animals with mirrors can improve ...

You probably didn’t but you will now. Put your fingernail against the glass. If the mirror is real, you’ll see a space between your fingernail and the reflection. No space? Smile and wave.