I am having the same problem at the moment with Fudge who is only 12 weeks. He hates being picked up and sometimes runs away from me when i try to stroke him in his cage. What I tend to do when he comes out to play is to sit in the play area quietly and stroke him in his hidey. He usually comes out in the end especially when he sees Patch letting me stroke her. I also always hold him in a fleece as he feels safer wrapped up. He is still very nervous when handled but i'm sure it will improve over time as it did with my others and Piglett will definitely improve too. Some piggies are braver than others and some just take longer to trust you so you just need to be patient!!