My kitten had fleas for roughly three days. She has only been upstairs a couple of times but I'm not 100% when she's had fleas but I know it's not very long. I've put flea treatment on the stairs and hoovered upstairs but I was wondering if it's necessary because it appears she has no fleas and I haven't seen anything around the house nor has any of my children been bitten and I do not have the time to go through a long procedure