When my son was a newborn, one of our cats would not let our landlords in to see him! She stood in front of his door and growled and hissed at them.
The children, in return, for the most part become very calm and quite joyful, and if some of their excitement on rare occasions translates into a hand accidentally striking the pet as they flail about in joy, the cat or dog just seems to know that it was not intentional and do not take offence -but do seem to re-evaluate as well and pick a different spot if necessary to ensure they are not accidentally stricken again.
What were those old sayings?...
Dogs are God's gift to Man to teach him about unselfish and total undying love.
Cats are God's gift of Humility, that such a godlike creature chooses to live among us, and that such a beautiful creature can come to love even Man if he is worthy.