About two months ago, I adopted two female cats from the local animal shelter. Both are fixed and checked out fine, they are not related, but were kept in the same enclosure at the shelter and get along well. They sleep together, give each other baths, and play.
The older one, Mandarin, has a yowling problem. She starts at different times in the middle of the night. At first I thought it was fear of being in a new house, but now both cats seem quite comfortable. The food/water bowls are checked and filled before bed time. Litter box is cleaned, also. There is nothing wrong with her medically, no UTI. She is allowed to sleep in bed with me and the other cat, and often does. However, she wakes up walks to a different part of the house and starts crying. I thought maybe it was the dark, so I leave lights on, but this hasn't helped. Now sometimes she does it in the middle of the day. The three of us sit down to watch TV and she'll walk off to another room and cry.
I've had cats for 21 years, but this is new to me. Any suggestions would be helpful.