Fleas are a nuisance, but once you've got a routine you're happy with and can stick to, it's a breeze to keep them away permanently.
I use frontline spot-on (your fosters are too wee for that yet so stick with what the rescue recommends for now) about every six weeks during spring summer and autumn, relaxing to two monthly over winter. This is less frequent than the recommended dose but I find it works adequately for us, I hate putting chemicals on them but this is a happy compromise I've experimented with for a few years now, and these dosages work for me.
For household protection I use Indorex once a year after my spring clean on all their non-washable sleeping and play places. This breaks the fleas lifecycle by making any residents infertile, and works on any eggs already laid. The continued use of frontline keeps the live fleas at bay, so one good treatment each year is enough to keep things flea free.
Bear in mind that all my seven furbies are in/out, and apart from Chubby
, they all interract with neighbours cats and have the occasional Off with local foxes too, so fleas are a natural consequence of their continued freedom.
The presence of fleas is in no way a measure of your care and love - even a newly de-flead cat can go out clean and tidy and come back with several on board, depending on where he's been snoddling.
Get the hang of a simple routine and forget about the problem, 'cos it will sort itself out.
