Ticks don't infest the home, partly because they are bigger and easier to see than flees, and also they are less energetic about finding a new host. They mostly sit on branches with their arms out waiting for a warm blooded creature to brush up on them and then they hang on. Fleas, on the other hand, have a super-long jump which they use to fling themselves toward whatever warm blooded creature they sense.
The issue with flees is you can kill all the ones riding around on your dog right now, but the eggs they lay hatch and then you have a thousand babies that are literally smaller than the dot on this i who are jumping around looking for the next host.
An adult flea is about , in size and an unfed tick is about 0 in size.
What you can do to really know for sure is make a household flea trap and see if you catch anything.
Here's what you do:
Keep animals out of the room where the trap is (don't want alternate targets for the fleas)
Create an artificial heat source. Easiest way to do this is with a lamp with the old style bulb. Have the lamp low, a table lamp set on the floor by a wall with the light shining right on the wall is good.
Next find something shallow and big to hold water. A cookie sheet or pizza pan works great. Put water in it. Now, add some dish soap and mix it around gently. The idea here is that dish soap disrupts water tension. I am sure you've been to the edge of a small pond and notice that certain bugs can walk on water, this is because of the surface tension. Fleas can walk on normal water, but with a bit of soap they can't and they sink and drown.
Put the water trap in front of the heat source.
Fleas can jump long distances toward heat sources, but can only manage one mega-jump per hour or so and that mega jump is generally a foot for an adult and half that for a juvenile. This means setting it out overnight can allow you to clear a small room or half a big room. These traps by themselves can never stop a big outbreak alone, but can help you monitor for fleas and in conjunction with medication to kill the fleas riding around on your pet, can eventually allow you to overcome them.
commercial flea traps work very similarly.