how to get nightshade motivated?

I read on these forums that cats love the laser pen, so i had a dig in my cupboard and found my old laser pen, and moved it around the room, but my cat wasn't even interested at all! she just stared at me and miaowed. after a while she just laid down and closed her eyes, how to motivate her? she was interested in it a bit and was looking at it but not for long, i tried putting treats down where the light was but she still ignored it! help please?

We tried it first when Zoey was in one of her playful moods. She was interested, but it took a time or two for her to figure it out. And we started out at night, when she could see it better.
Now she runs over as soon as she heres us pick it up (there is a ring on the end that makes a sound when it hits the side of the laser) or when she sees us hold it. It has also been a great ice breaker to get her to approach visitors.
We are on out third set of batteries this month.....

hmm, ok i will try it later in the evening because the cat has gone outside in the garden i think i will get her toy mouse and put some catnip in it and see if that motivates her.

I've tried everything in the past 2 days to get her motivated to play with the laser pen, she just won't play with it! i try to make her excited and give her some of her favorite toys to get her in the mood but she still ignore it, she just stares at me and again miaows, i tried in the morning and at night now and i have tried with treats, the only time this cat is interested in playing is when i have food in my hands XD maybe i just need more patience with her? because she just ignores the pen completely, i put the laser pen near to her so that she can sniff it just in case she is scared of it but after that nothing....