One of the purposes of having four kids in six and a half years was so they'd go through the stages of their childhood at roughly the same time. I could throw them in the bath together, they'd all take swimming lessons at the same time, and they'd all (yikes!) go to college around the same time. I really didn't want to end up pushing a stroller at Bryce's high school graduation.
But I'm beginning to realize that I might not have had them close enough together. When Bryce was a baby-- he ruled the roost. As soon as he could crawl and pull up, we babyproofed the house and got rid of all of the tchotchkes that could end up in his mouth. Other than emptying our bookshelves and VCR tapes on a daily basis, he didn't get into too much trouble in the "moblie but still stupid" phase of babyhood. It was pretty much the same scenario with Annie. Bryce had toys that she'd get into, but since he's less than two years older than she is, he'd get annoyed when she'd knock over his blocks or get into his puzzles, but other than getting sat on or knocked over, she was never in any imminent danger. Pretty much ditto the situation for Isaac, except that he had two older siblings who would scream if he got into their stuff.
But in the last two years, Bryce and Annie have moved on from blocks and stuffed animals to Polly Pockets and Star Wars action figures and Legos. I keep the kids' doors closed most of the day (and they have to keep all of their "big kid" toys in their rooms instead of the playroom) but in a single day the other day, I found a Lego walkie talkie, a Polly shoe, part of a South Beach Diet bar wrapper, and a leaf in Maren's mouth. And she was sucking on a Thomas engine too, so even if she hasn't choked to death or died from Polly magnets in the intestine, she'll probably be done in by lead paint.
At this point, I'm glad for the 100 fewer kid hours in the house each week. Maybe, just maybe, it will decrease the mess to the degree that I can keep up with Maren and what she puts in her mouth.