help with movement and wall climbing!

Hi, i'm making a mob that can climb walls (I was able to do that) but the only problem I have it's that when the entity reaches the top of a block it dont walks in the block like spiders, they still in their place floating some time (Wich is obvious because I didn't'programed it to make that) I will send a screenshot, I just want to know how to make it be in the bloc