Thanks ladies, your discussion is very helpful. He is doing well, but restless legs are getting worse

he's hunting everything that moves, including my hands and feet

not pleasant as I bleed very easily.
When I rescued him he had some fleas. I was advised not to use any chemicals before 8 weeks, so I bathed him in very warm water and a neutral glycerine soap, washed and dried him thoroughly, brushed his coat gently with a comb over a white towel. That made it easier to catch the fleas and put them in alcohol. Then, I hoovered the apartment, his clothes, bed, everything I could really, and will do it every week to ensure that no flea eggs will remain to hatch. I washed and dried all clothes that were in contact with him (mine included) in high temperature. I'm keeping an eye on him to see if there are any fleas popping up, he's so tiny that this is an easy task, at least for now, he's growing fast, he was loving to hide under the furniture but now he's having a rough time to get in there

I wish I could post a video, he's is so funny!
P.S. Tell me more about this comb, CLKD, that's interesting!