Lennie joined OCR’s clowder nearly 6 months ago and we’d like to say that he and Stanni are fast friends — but we can’t. They have, however, learned to co-exist. That’s progress.

Suggestions for introducing a new cat to a resident feline are all over the Internet. Among them: The Humane Society, the ASPCA, Petfinder and, of course, Cat Daddy Jackson Galaxy.

The overriding theme in most tips is time, patience and keeping the cats separated for a while. I would also like to paraphrase the ASPCA animal behaviorist who tested Lennie. She said you can do all the tests in the world and ultimately it’s a “crap shoot.”

Time, Patience and Crossing Your Finger and Paws

And then there’s Lennie and Stanni. At age 3, Lennie was the first adult cat I adopted. Lennie did not react to other cats when he was tested and 14-year-old Stanni lived with other cats her entire life without major issues. I figured this would be an easy meet-and-greet. Ha!

Lennie spent his first night in the bathroom surrounded by a warm bed, toys, food, litter and frequent visits from me. The next day, we let Stanni sniff around near the closed bathroom door. Her ferocious yowl nearly curled my stick-straight hair. Still, we were hopeful.

Stanni’s brief sightings of Lennie evoked the same response. The confines of a New York City apartment and long stretches traveling made a supervised introduction necessary by Day 3. Stanni — my sweet, fat mushball — hissed, chased and swatted Lennie with the intensity of a seasoned street fighter.

Every friendly overture Lennie made was met with growls and swats. The terror and confusion was written all over his face. But one evening, both cats greeted me at the door. Food fights slowly became little more than Stanni occasionally bullying Lennie. But over time, Lennie began to asset himself. Suddenly, Stanni allowed him in the bedroom when she wasn’t there. They even sit at opposite ends of the living room without incident.

Stanni is still not pleased about his presence. Sometimes, she looks at him, then me, with an expression that seems to scream, “Is he gone yet? No. How about now?” Ultimately, my girl appears to have decided that rolling around and showing her fluffy belly is worth more to her than chasing some dopey guy cat all day long.

They are not pals but they eat together and the hissing is little more than the remnants of habit.

Lennie and Stanni — like any two creatures in a new relationship — needed to find their own way. When introducing cats, it is important to have knowledge but never forget that all the online tips can’t factor in each cat’s unique personality.