There are so many comparisons to pets and babies. I think Laci has picked up on these similarities too. Calvin has become a very nice pet for her. She often calls him "Boy" as in "Here, Boy". Now that he is he crawling, she plays fetch with him. And to confirm further that he is the family dog, last night while she was eating dinner, he sat under the table waiting for crumbs to fall.
He is also starting to get really attached and doesn't like to be left alone. I went upstairs the other day and heard him crying. A few minutes later, Laci started yelling "Mom, come quick. You have to see where Calvin is." Where could he be? I came downstairs and found him in the laundry room next to the garage door. The poor baby had thought I left and was trying to come after me.