i have got a new baby in the house whos a week old now. plus have a black & while domestic cat. we have got a problem at the moment with are cat where she has a constant problem trying to get at my boys cot/moses basket & walking around him when we try to change him. my theroy behind this is the cat probably feels left out when a new baby arrives in the home. how do we sort this out & change are cats behavour? if it came to it we will rehome the cat , but its a last option.

The cat is probably curious. From the cats point of view thay've had a new thing that makes noise come into their home and the cat probably just wants to know what it is. Give the cat time to settle with a new arrival, but do make sure you give some time to the cat too.

yes that thought was crossing my mind too,it has got the wife panicy as she fears the worst,probably like the cat is jelous of the new arrival. in my view the difference between the both .one keeps you away at night ,the other does not.

Also the cat may be able to smell milk on the baby. The cat will see the moses basket/cot and anything like that as a nice warm bed to sleep in, so lm sure you dont need me to tell you to be extra vigilant of the cat getting in these places.
Give lots of hugs to your cat as they can be ultra jealous creatures, and hopefully you will have no problems all living under one roof. All the best

I cannot imagine for one moment a cat would look at a moses basket with a wriggling crying baby as somewhere nice and quiet to sleep!

OP I had a rescue cat when both my kids were born. He was curious and that was it. Never hurt them, never tried to sleep in the moses basket. Cat was a bit clingy to begin with more so due to noise, stress of a newborn and change of routine. But he soon settled down and accepted it.