Wow, a combination of cats and dogs that are both inside and outside the home. Near a guaranteed assurance of Fleas!
Kerosene is a very old tool for killing Fleas and other bugs, but dangerous as its fumes are very flammable.
If you are feeding mice /rats to your snakes! The mice /rats are another source of fleas.
Yes, you can do this yourself, but you have to be really diligent starting for the basement and ending in the attic, assuring you target every room, closet and storage area and 'everything' in those areas. Fully around the foundation of your home with extra attention at the doors and lower windows for the basement. Clean around the home and spray the ground a full meter (3') from the foundation.
With luck, you will kill most all bugs while you are at this!