DEAR JOAN >> We have been feeding a stray cat for about two years. Until she became friendly enough to eat in the house, I was feeding her on the patio under a small A-frame “tent,” if you will.

Under the tent is a doormat for a little comfort. During the outside feedings, we had other cats, as well as a raccoon and an opossum eating her leftover food. When she started eating inside, that problem went away.

Her small milk dish though, still resides on the patio. She usually sits under the tent and drinks the milk with her tail sticking out the back of the tent. It’s cute.

Last week, I flipped on the porch light and saw a tail hanging out the back of the tent, but it wasn’t Kit. When I turned on the light, some small animal ran out the front, turning left toward the garden and the back fence.

The animal was dark brown with short hair and a cat-like tail, but unlike a cat, it had short legs and was smaller than a small cat. What I thought curious was that as it ran, its tail, which was furry, was flat on the patio. Also it had a mouse-like head with small eyes. I presume that it went up and over the fence.

I looked online for California mammals and found nothing that looked like this. Do you have any idea as to what it might been? Could it have been a very large roof rat?

— Art Zikorus, San Jose

DEAR ART >> We probably will never know for certain what animal it was, so we can only deal with possibilities and probabilities. Let’s start first with the rat.

Roof rats, which are black with white underbellies, are about 8 inches long with a 7- to 10-inch tail. Norway rats are brown and are 10 inches long, but with a shorter tail. The problem with your visitor being a rat is that rats don’t have furry tails.

Another possibility is a juvenile opossum. They have rodent-like heads and, when young, they are dark in color. They also have small ears and short legs but alas, their tails are more hairy than furry.

Last on my list of suspects is a long shot — a river otter. A full-grown river otter can measure about 2 feet long, including the tail, which is covered in fur, is thicker at its base and tapers down. Younger otters, which are starting to venture out on their own, are somewhat smaller than the adults.

Although otters are water creatures, they come out on land frequently to get from river to creek, and to look for food.Of the three suspects, I’d put the opossum top of the list. Readers, your thoughts?

DEAR JOAN >> We hear birds are sickened with salmonella transmitted by pine siskins and finches from Canada. Spread is occurring at feeders and birdbaths. What do you recommend?

— Sheila McGann-Tiedt, San Jose

DEAR SHEILA >> Salmonella, which is spread by the feces of an infected bird, is killing songbirds in the Bay Area. Some wildlife experts recommend emptying birdbaths and taking down feeders for three weeks if you see a dead or ailing bird in your yard. The feeders and baths need to be cleaned before being put back in service.