Noticed that after adding some water to top up. A couple of the shrimps will swim to the water surface, and they seemed to be skirting the brim of the water. After that they will crawl on the side of the tank and then go back to the ground. Is this normal?

Are they reacting to the water changes. I only add about 1-3% of water each day to compensate for the evaporation. Is this OK?

The water I used is from a basin of water which I filled up the day before.

Kindly advise this newbie, you veterans out there.