How brave is this bird? (Animal behavior question)?

We have a robin, who built her nest in a hanging flower pot next to a big plate glass window. It's in plain site of our exercise area, which faces out onto the deck. After she had laid her eggs, she discovered we also have two very curious kittens, who like to sit at the window and try to jump up towards the pot. The robin seems to have a good attitude though. When she gets disgusted with us, she just turns her back on us. The 2 chicks are pretty big now and we'll keep the cats inside until they have fletched and flown off.

How brave is this bird? (Animal behavior question)?
kinda strange since animal instinct tells it to evade whatever's pouncing at it. but either this bird's brave or knows there's a barrier between itself %26amp; its threat. or maybe your kittens don't look threatening(?). possibilities...
Reply:One thing I can think of. Most likely the bird can not see what is happening inside the house behind the glass window. Usually there is a reflection of itself in the glass, esp. when the sun is bright outside and it's dark inside. Try to go outside during the day to see if you could look inside and see your cats!