Guinea pig unusual sleep schedule?

[richguinea]

I recently stumbled on this interesting article with many guinea pig facts. However, one of the facts was that guinea pigs aren't actually nocturnal even though many people claim to see their guinea pig awake in the middle of the nights. Instead, they take 20 to 30 minute naps throughout the 24 hour day.

The thing is, i'm pretty sure my guinea pig does not take 20 to 30 minute naps throughout the day, but rather sleep at night. I work from home and my desk is right next to the cage. I am always overseeing what they are doing and they are certainly not sleeping.

Is this something i should be worried about? Is it unhealthy for them to have such a similar sleep schedule to humans?