how ever you indroduce the animals you might like to try rescue remedy for all of them I have used for stray cats for years it has a great de-stressing effect
4 drops each in their water or food or you can put some on their eartips it is a totally harmless flower remedy from Bach remedies which can be found at Boots,Tesco's and just about all heath shops.
students use it before taking examinations for the same reasons

good on you for taking two recue cats look at my signature it was true then and is just as true now.

G

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In Egypt,the cats...afford evidence that animal nature is not altogether intractable,but that when well-treated they are good at remembering kindness
AELIAN(roman writer)

http://www.soyouhavelostyourcat.co.uk