What do you guys think?

So currently me and my grandparents are taking care of my cousins since cps took them away from my aunt. The oldest one is a girl (10 years old) and the youngest one is a boy (7 years old). Now we've been having trouble with the youngest one. He's been pushing my grandpa/hitting (he does this to all of us, not just to him) if he doesn't get his way (he's been like this even before cps) he also takes speech therapy but I don't think that's what's causing him to act out because he speaks well now ever since he got help. Other then that with homework, it's like he forgets everything he's been taught and he just circles whatever or guesses what a number is and at times he knows the answer (He's also failing every class). His mother said that she had him evaluated for ADHD but that they never called her back to tell her if it's what he had (which I know she didn't take him, she just said she did just to say so and I know they tell you right there and then if it's what he has) When we ask him to do something he'll say "huh" or ask "why" and then he'll repeat what you said to himself. He also does this thing with his hands, like if he gets something right or excited, he'll shake them in a way as if he's doing spirit fingers. Could be a habit? He also pees on himself because he refuses to get up in the middle of the night because he's scared. Another thing that's irritating is if you're eating, he'll ask for you to give him some even after he had ate. He just asks because he sees it. Now from what I know, my mom told me that my aunt was the same way when she was younger, all the things he does, she did. So I was like what if this is some genetic thing? Or it could be that he has problems because my aunt was drinking and smoked all the way till she was 6 months pregnant with him? I've tried reaching out to the cps lady to see if she could help us get a therapist to talk to him but she said she would talk to the school about his classes and try to get someone to talk to him (but in all honesty I think his teachers don't want anything to with him because of the way he is, last year they kicked him out of summer school and said he didn't need it and it seemed like he went just to mess around)I just know something isn't right with him mentally. The oldest one has her problems too, but she isn't like him. We can deal with her but my grandparents are giving up on the youngest one and we're trying, it's just too much.

Any thoughts?