Is it possible to have a sump pump without an inlet (input) pipe? Is this normal? I am told my house has a sump without an inlet, but instead many small holes in the container that allow water to penetrate the pit (sump). The discharge works in a regular way. The sump motor is always running during heavy rain or snow. I am wondering does the lack of inlet pipe (drain pipe) cause excess water into the pit? What exactly would be the approximate area around the pit allowing water to flow in without an inlet?
Does the lack of inlet pipe (drain pipe) cause excess water into the pit?
No, if anything, it slows down water getting to the pit. With a pipe, water from the other end of (and all along) the pipe would flow from the soil/drainage rock, into the pipe, and to the sump. A pipe is effectively an extension of "tiny holes into the pit" across a wider area of the basement.
Without a pipe, water from where the other end of the pipe isn't flows through the soil (or drainage rock) to the sump, which is a somewhat more torturous/slow route.
Unless parts of your basement away from the sump are flooding, it would appear that the drainage rock layer under your slab is adequate to get water from other parts of your basement to the sump, without needing a pipe.
The fact that your sump pump runs a lot during rain/snow events indicates that you need it to remove water before it can leak in, not that having pipes instead of a perforated pit would change that. If you'd like it to run less, address the usual concerns - grade the surface soil away from the house for at least 10-12 feet, install gutters if you don't have them, and make sure the gutters drain into pipes that take the drain-water away from the house, etc.
A sump pump without an inlet won't have any way of getting water into it to be pumped out. It would, therefore be rather useless.
A sump pit without an inlet pipe but numerous holes (such as yours) will allow water to seep into the pit where it will make its way to the sump pump's inlet and be pumped out of your basement.
"Normal" is probably defined by when the sump was installed. Our house has a sump pit in the "root cellar" that was probably added in the 1940s. They broke a hole in the concrete floor all the way down to the dirt, dropped a brick on the dirt, and the sump pump sits on top of the brick. Once the float is high enough, it kicks the pump on and out goes the water.
My in laws added on to their house in the early 70s. They have a nice pit with a plastic liner. There's an input pipe from the "root cellar" old portion of the basement, but, I don't think there's an actual inlet from the new portion - water just seeps in from there.
I haven't a clue what modern (2000+) code calls for, but so long as the water can get to the pump inlet and the pump has power, it should be doing its job.
You're much better off having the pump running nearly constantly during a storm than you are having the water back up into your basement. You may want to look at adjusting the float so that it has to be higher before the pump kicks in, but then you risk overflowing the pit. You could also consider adding a 2nd pump (with its own exit plumbing or upgrading the pipe size going out to handle the additional flow) to handle more water coming in than your current pump can handle. It also makes for a nice emergency backup should one pump die during a heavy rain storm.
The small holes keep the soil and rocks in place. All the small holes allow the water to enter the sump.
I have had homes with this exact system and they work fine.
If you have a septic system most drain fields work the same way but in reverse. The water is flowing through the rock / soil under the slab. When it finds a place to enter wether it be through the concrete or through a perforated metal container the water takes the easiest path. Then you pump it out.
Some systems do have perf pipe to drain to a sump these likely are the pipes you expect but not all systems have that. The better rock bed under the foundation the easier it will drain the entire area.
The proof it’s working is the pump is running when it’s raining.
If you want your pump to run less you have two options : a bigger pump , or a second pump. I had a neighbor that had 3 pumps in the same sump . One ran most of the time , the second also ran if it had rained during the last week, the third also ,also ran if it was raining . He had a finished basement , my house was 100 yards away with a crawl space and a single pump. He had 1 or 2 available spare pumps as pump life was not that long.