Has anyone been bitten? Are you genuinely itchy. or just reacting to the thought? Red bumps on anyone? If not, it is hard to tell from the pics but I would suspect fruit flies or similar, or possibly swarming ants - fleas don't have obvious wings like that.
If you're not getting bites & the pup's not itching... no need for fear. I'd just vacuum the daylights out of the house. Get you some Irish Spring (original) bar soap & set it out near all doors where bugs might enter your home. It helps repel a lot of creepy crawlies & so does pennies. We used to keep a bowl with a few pennies & a dab of water, they don't like the scent I guess. But the soap, you can just cut chunks up & leave it where it doesn't get soaked by the rain. Smells pleasant to us humans & bugs & critters don't like it.
Google fruit fly. That’s what it looks like to me. If they have wings they aren’t fleas. You can get them just by having bananas on your counter. I had a bunch a few summers ago and made a trap I found instructions to on the Internet. You get a glass and put some red wine in it and a few drops of dish soap, then cover it with Plastic Wrap and if it doesn’t stick to the sides of the glass use an elastic, then cut a little hole in the plastic wrap, the flies will go in and then not find their way out.