litter box problem......

My cat is a 2 year old female, and she has a problem with the litter box as soon as it gets dirty. I have 2 cats so when the other one uses the litter box the 2 year old wont go in after her then winds up using the floor...Why? Also I have another question my two cats use to be really great with each other almost like the oldest one was being motherly to the youngest, but recently we moved from an apartment to a house with there own yard so there able to be outside cats but since we let them outside there more aggresive with each other. Almost every time the youngest one walks by the oldest she smacks her paw at her and growls. is there a reason for that?......

Answer by Kate
Hi
To answer your first question. cats do not like to share litter trays because the scent of the other cats urine will put them off. Remember cats use their urine scent to mark territory. So when your cats can smell the other cats urine it is like a warning signal to stay away. It is always recommended to have separate litter trays which are not near to each other.

As for your second question. well it could simply be a case of trauma aggression. this is a weird behaviour caused by anything that can upset or frighten a cat. So it could be a loud bang, a strange smell or even as in your case a new home and experiences of being outdoors. the fear or uncertainty is blamed on the other cat (for no apparent reason) and that is where the aggressive behaviour comes from often aggression is a sign of fear rather than anger etc.

You may have to try and re introduce your cats to each other using the method described on this page
https://www.our-happy-cat.com/introducing-cats.html
to try and re build their confidence in each other in safe and controlled environment.

Hope I have been able to answer your questions for you

best wishes Kate

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