I have a five month old kitten and we have had her for almost two months. As expected, she still loves to explore the house every day...especially at night.
. Exploring, playing (which may result in knocking things over), is part of kitten hood, and I can't imagine locking her away for hours for doing what comes natural to her. Cats pick up many of their social skills when they are kittens; therefore, locking them up (away from human contact + other experiences) may cause bigger problems in terms of behaviour in the future.
I would suggest you kitty proof your house like you would for a baby. I had to do that when Sienna came into our lives. She still managed to get into certain things (like trying to drink out of our cups on the table and tipping them over in the process, playing with the straws etc.). However, we're currently working around that by using bottled water instead.
Just try to be creative, provide them with scratching post, kitty condos etc., and in time it will pass.
On a side note, Sienna discovered how fun Christmas time can be when she noticed mommy wrapping gifts today. Needless to say, it took me quite a while to wrap with a kitten trying to help
. But I probably enjoyed her new experience with this more than she did. lol