I think the brown boy is a tri as he has eyebrows coming out. Interesting enough we usually put less in each box as we do not want them getting caught under and missing a feeding if Dennis falls asleep or I get extra busy. But this crew finds their way out and enjoy the undercover experience and then when it is to warm they crawl back on top.
As you can see, they are plump beings. I do hold each puppy 3 or 4 times a day in purpose. Two of those times is when weighing and the other 2 is just because. The odd time I will hold them just to do so over and above the usual 4 times a day. I do this so they get used to being handled, caressed and they get used to the smell. What you do early on is important as it conditions them to people. Once their ears open, they will get used to sound. Eyes usually open the same as ears. How can you tell? If you drop something they will startle. We don't drop things on purpose but we vacuum and do all the normal things us crazy humans feel we must do.