It's the cover making a weird sound... I've seen online videos that recommends to just have it removed... But 99% of the time, my vacuum cleans when no one is in the house, So its not a big deal. Personally, I use my robo-vac to clean the floor/carpet every day. Sucks hair/dust and small things on the floor. You still need a bigger vacuum (Dyson V8 for me) for that once a week sweeping... An even bigger one for the mattress/sofa Even if you have lots of furniture, as long as the vacuum can fit under or around it, then you're fine.