I have got an animated toy bird, it isn't suitable for them to actually play with so I just hold it in front of them, press the button and the bird moves and makes various chirruping noises. Mitzi was funny last night, she put her beak right up to the bird's beak and was saying "hello".
I find it amusing when Manzi tries to talk to things that won't answer. Like he's trying to figure out what exactly it is. Once, when he was free flying, he went up to a squirrel and said "hello" to it several times. He finally gave up.