Once they are acclimated and the water condition is good, they will try to play with you. Their behaviour is not like fish, more like dog. LOL!!! There are a few interesting behaviours you could try to observe:
When you put your head close to the tank wall to look at the shrimp, they will swim and suck on the tank glass right in front of your eyes. Kind of trying to get your attention.
When it is sucking on the tank glass not moving, use one finger and put in front of it then wiggle. They will greet back by waving the fin.
One thing you need to take note when keeping with shrimp. They love to hog on food. Meaning, they love to hide the food under their mouth or tummy to prevent others from eating. If you see such behaviour happens, try to feed during the period when your lighting intensity is the strongest. When light intensity is at the strongest, it will be Oto's sleeping time.
This is another variant of Otos worth collecting:
Their body length is about 0.5 to 1cm longer than the one you have. It still consider quite small.