It really does take time. They are prey animals and tend to be fearful until they are accustomed to people. I generally try to spend short amounts of time frequently with new arrivals. At first they will be skittish, but they will improve with time. I often give them a snack before patting them, or a snack after I return them to the cage as positive reinforcement. We've just gotten a new pig, Hadley, who is about 3 or 4 months old now. She's been with us for about 2.5 weeks. She was definitely fearful at first, but within a week or so of regular handling, a couple times a day for short times, she has settled down and will now squeak contentedly when we pat her, will take food from our hands while on our laps, and will lay down and show by her body language that she is relaxed while being handled. She does still startle easily if there is sudden noise or sudden movement, and she does not like to be initially picked up or to be touched while she is in the cage or having floor time. I find that takes the most time... first they get comfortable sitting on your lap, but it takes longer for them to let you pat them when they are standing on their own (with the exception of very new pigs who just decide to freeze as a defense mechanism and hope that you stop seeing them!)
