Behavior change of siamese cats between two homes

Question
Hi,
I have kept Siamese cats for many years, and currently have two brothers, one
a seal point, and one seal tabby. They have always been timid, but are always
together and seem to get along well.  About a year ago, we bought a second
home and from this time, we have started taking the cats when we go there at
weekends. When we are here, we have serous problems with overnight
yowling and aggressive behavior but there are instances of this trouble at
most times. We initially thought this was from the tabby as he is most vocal,
but it seems this is in response to the seal point and actually defensive
behavior, yet the seal point is usually the most timid. As soon as we go back
to the main home, all seems back to normal. When we tavel, we use a travel
tube which they share, and during this time they again seem fine.  They are
clearly not happy and we need some help. Can you shed any light on this?

Answer
Kim,

They are stressed in unfamiliar territory with new smells, sounds, etc, and they have a disruption of habits and association. Cats are creatures of habit. They are not happy about the 2nd home.

I use a large dog crate (48x32x30) that I got at Petco to keep cats in when introducing new cats or cats in a new area. It has room for litterbox, food and water, small cat carrier without the door for a bed and to get up on, and they still have room.  I am attaching a picture of it. You may want to try putting them in one of those so they can snuggle together and hide if they want and not be overwhelmed and upset about the situation. You can let them out for short periods of time then put them back in their 'safe house'.

Or you can let them stay at home (the first one) where they are comfortable and happy, and not stressed, while you are gone for the weekend to #2 home.