Just adopted adult cat - 2 odd behaviors

Question
Hello,

I just adopted an almost 4 year old adult cat named Pita. She's
adjusting, and I think she's doing really great. 24 hours and I'm
already in love! Anyway, since she's been here I have observed 2
behaviors I've never seen before, and we rescued many, many
cats growing up.

First, if I go into a room and close the door behind me, like into
the bathroom, or into the room where our hamster is, Pita will
wait a few feet outside the door for me to come out. When I
come out she will hiss at me, but, it's not a normal threatening
"back off" hiss. Her ears are up, and she looks happy, not ears
back and angry faced. She'll let out a single half hearted hiss.
Then she's fine. What does this mean? I get the impression it
means "I don't like you disapeering like that!" but I'm not sure,
I've never seen a cat do something like that.

The second odd thing I've noticed is what seems like a strange
fear response. Certain sounds, like yardwork outside, or the ice
maker filling up, seem to make her mad or scared. Instead of
hissing, or hurridly running away, she starts making this low
growling sound. Sometimes it starts low and moves up in pitch,
sometimes it's just a low (but loud) growl. She gets down close
to the floor, continues growling, and walks very slowly under
something. She'll continue growling until the sound goes away,
and then she's back to playfull and normal.

Neither of these behaviors are frustrating or alarming, but I
thought I had seen all the tricks that felines pulled out of their
bag, these two are very different then anything I've seen. Are
these just stress repsonses to her new home, or something else.

I appreciate this service, and thank you in advance for any
insight you might have.

Thanks!
Adam

Answer
First congratulations and thanks for adopting an older kitty in need of a home. As for the two issues you raise, they are probably things that will change with time. You do not mention if you were given any history on her past but these behaviors both sound like fear reactions to me. She follows you to the room becasue she feels secure in your presence and wants to be with you. I don't think she is hissing at you when you open the ddor as much as just being slightly alarmed at the door opening and not knowing if its just you or there might be a surprise behind that door. The hiss is half-hearted because it is an immediate response to the door and whatever danger might be behind it and the she sees you and she is immediately OK again. I am quite sure she will get over this one fairly soon. You could try leaving the door open a slight crack. Her curiosity might cause her to put up a paw and open the door and she will see al is safe. As for the response to noises, yes it is a fear response too. The low growl is a common response to threat. SHe may have been in a situation which conditioned her to be defensive like this. It will take time and adjustment for her to get used to the everyday noises of your home and realize that there is no real threat there. Again, I am sure with time she will be fine. If you want to try to console her when she is growling, do it very cautiusly because you do not want her to perceive you as associated with the threatening noise. But you could try distracting her from the noise by tossing a toy or getting out some treats. It may help but she does need to adjust with time all the same. If anything else happens or ou see things getting worse or changing, feel free to contact me again and we can see if there is any further problem, but right now I think this is not unusual behavor at all and time will fix the problem. Meanwhile just give her the love she needs and enjoy this new little member of your family. All the best!