Very cute! Guinea pigs are prey animals and naturally very cautious. It's very normal for them to be stressed upon moving into a new environment and to either freeze or hide. The best thing to do is to give them a few days to settle and then begin gentle handling, perhaps scooping them up in a cozy to avoid stress. I usually let new, cautious guinea pigs sit under a blanket while I gently pat them when they are new. Being hidden makes them feel more secure. I also make sure to offer some treats during lap time. Once they figure out you aren't a threat, they will begin to calm down a bit. I also had guinea pigs with young children (my kids were 6, 4, and 2 when we got our first pair of piggies), and it's good to start modeling from day one how you want the kids to treat the guinea pigs- move slowly, be gentle, remember they are living things and not toys. We had ground rules and only let the kids hold the pigs if they were supervised, and I would do all the transporting back and forth between cage and lap (because guinea pigs can jump down if startled and easy to get back home and I didn't want anyone to be dropped.) I would supervise lap time to make sure the pigs were under control and the kids weren't being rough with them at all. As the kids have gotten older (they are now 14, 12, and 10), obviously what they are able to handle as far as care and responsibility goes has increased. Our pigs always quickly learned that kids are reliable snack providers and ended up loving the kids, my son apparently now works for them as they expect him to give them veggies every morning before he goes to school and wheek at him until he follows through! Hope this helps a bit, lots of luck with your new pigs!
Edited to add: At first, kid-related noise will probably be scary to your pigs, but in my experience they will adapt to it pretty quickly. Our pigs are in the living room and really quickly learned to phase out kids running by, TV noise, etc.
