You’ve probably seen the random baby with a giant hole down the middle of their pants. What appears like an unsettling solution to solve the urge actually makes a lot of sense. Do they make them in adult sizes?

1016_wtdwAlthough not quite as common as they were 20 years ago, the world-infamous split-crotch pants are still highly visible throughout the modern China. It’s when wearing these odd trousers that toddlers often practice their first staggering steps—while displaying their full glory—at residence gardens, around the neighborhood and in any bus/metro. Known in Chinese as Kai Dang Ku, the open rear-end apparel serves one major function: time savings. No more soiling clothes or wasting money on diapers when practically any surface can become a makeshift toilet.

In older times, when resources were generally scarce, people found it extremely helpful to use this method when taking care of toddlers. Even when diapers were finally introduced in 1998, they were still considered unnecessary luxury goods and a privilege to be used only by rich people. But a shift is dramatically happening. By 2010, these mobile toilets had grown into a 21 billion RMB industry.

Grandparents, for example, argue that they once raised their kids using the same special pants and they turned out just fine, so why is it suddenly unsanitary or inappropriate to show a baby’s behind today?

Whether to use open-crotch pants or diapers when raising a child has become one of many controversial differences or disagreements between mother and daughter-in-law’s across China. However, countless reports have pointed out that children who wear split pants are becoming potty trained earlier and more effectively than those who use diapers.

Traditionally, these pants were used so a child can leave the house and walk around freely until they could properly use a toilet. This stage will last from 1 to 3 years of age.

In the West, parents don’t dare to start any toilet training unless they already know their kid’s bathroom habits very well and also that the young one begins to show an interest in using a toilet or following simple instructions, which all normally starts in during the second year or soon after.

Meanwhile in China, just putting on a pair of open pants isn’t the beginning of toilet training. Rather, the whole learning process starts merely days after the baby is born when the caregivers already tend to overtly instigate the child’s peeing and pooping with little tricks.

Before and after sleep, feeding, drinking or whenever there’s time, the baby will be held, popped into a squat and the sound of running water or urine will be imitated by whistling or making “ssss” sounds. Through conditioning, the child will learn that whenever they hear the sound or are holding a squat will mean it’s time to release.

Spilt-crotch pants are certainly not a Chinese-wide invention, but were a logical tool used by housewives. In the past, women needed to do a tremendous amount of work in the house and field, even when a baby was still in swaddling. After the infant was able to walk, they were usually left to play and largely function on their own.

During these times, the parents’ only concern was making sure the cloth diapers were clean. As a shortcut, the crotch area of the pants was left open, so that when the baby needed to squat, the pants would open, the business would be done and there would be little to no mess to clean. It was such a genius idea that it spread all over the village and the country.

Besides that, there are a few other reasons to be diaper-free, like avoiding skin rash due to prolonged wetness and choosing a more ecologically-friendly option that doesn’t require excessive washing or generating extra trash.

Right now, a hot debate looms between the young parents and their parents or grandparents on the issue. Grandparents, for example, argue that they once raised their kids using the same special pants and they turned out just fine, so why is it suddenly unsanitary or inappropriate to show a baby’s behind today?

Many parents also consider another major issue with using the split pants: toddlers will form a habit of answering their calls of nature wherever and whenever they want, which is actually quite the opposite of potty training. In other words, even when kids successfully finish the training, they still tend pee under a tree, out on the grass, beside a pole or straight on the pavement because they’ve already done it for years.

Many Chinese people today show an incredible tolerance toward this kind of behavior. After all, plenty of harmless, naked backsides of children are often seen all over the place.

Possibly to appease an older generation, some parents combine the use of diapers and split pants even before the child can walk by wrapping a diaper inside the pants. The convenience of the act isn’t just limited to containment of pee or poop, but also makes for an easier diaper change without needing to remove the pants.