plenty of ants, flies, mosquitoes, wasp, and whatever you can think of.

You may have a wasp nest around your property or a neighbours property.

Do you have any pools of water on your property that may attract the mosquitoes?

Flies and ants are normal I would say.

In the house you can start by lowering the humidity with a dehumidifier and/or by lowering the AC.
Look for any holes in the exterior of your house and patch them up.
For the ants, get the ant poison that they take back to the nest so you can kill them all.
Don't kill spiders and other predatory insects as they will get rid of the smaller ones for you. Once they're gone you can kill the predators.
Diatomaceous earth will help kill the crawling insects.

Maybe it's because you have that huge vent hole in your kitchen wall.

bjl

Your going to have to find their entry points and close them correctly (and effectively kill what is already indoors). A cat won't help as much as you think.
Ants come from holes in the structure. They can setup nests in the structure which you have to kill the queen to destroy the colony.
Flies come in through holes, when you open doors or unscreened windows and can lay eggs indoors which hatch.
Mosquitoes come in through open doors and rarely through cracks.
Wasps come in through open doors (rarely) and holes in the structure and can make nests in attics, walls and out of sight areas.

If you have a dirt crawlspace this often multiples all bugs.

I use insect sticky pads that you lay on the surface. I put them in various places in the basement, usually around the bathroom door and tape them to the floor so the bugs can crawl onto them with ease. In this particular case, I laid 5 or 6 right across the doorway on the floor, as that was the room they seemed to be coming from. My gawd they catch a lot at times, especially in the summer when they are the most active.

The strips are roughly 3"X5" and are laid flat. I believe they come in packages of 4 or 5. The last batch I purchased came from Canadian Tire, but when I was there the other day, they had cleared out a lot of that type of product.

My cat has learned the hard way not to step on them, and now finds them quite fascinating, especially the larger spiders that seem to take forever to die.

i found some cracks around the house, and the slope towards the foundation, so there is water accumulation. looks like alot of stuff needs to be addressed before the bugs start to decrease.

What's the RH% in your home? In your basement?

bjl

Speaking of which, I had a whole bunch of wandering wasp in my kitchen for over a month, they weren't agressive but quite the opposite, they seemed very confused.
I kept looking all over indoor but couldn't figure out where they came in, last week I went on the roof and lo and behold, saw a bunch of them coming in and out of my unused chimney and I happen to have a clean out inside my staircase from my kitchen going to tbe basement, so they were getting in thought that cleanout door, find a bunch of dead ones there.

So i had my GF smoke them from the clean out while I used a soapy water and sprayed them, used 2x 1L, I then took shopvac and put in some soapy water in there and proceeded with caution (fully dressed with a mask, gloves and goggles) to vacuum them, once they were all gone, I lowered the hose down into the chimney, I think their nest was 3-4 ft down, so I had to duct type 2 hoses toghether, it must have been where the protective grill was to keep animals out, sucked the hell out of them, seen none since

On a side note, we tried to record the inside of the chimney with a LED lantern and a GoPro, the GoPro fell because it wasn't securely attached but luckily I was able to pick it back up with the shopvac