I'm greatly prompted to tell you about the First Avenue felines of Beekman Hill, New York City. They are the cats of Return Engagement, the thrift shop operated by the Society for Animal Rights Inc.
The cats are more appreciated than ever by us neighbors because it seemed for a time that they might have left Beekman Hill altogether. The apparent disappearance occurred when Return Engagement was in the process of exchanging locations with the next-door flower shop. Brown wrapping paper covered the windows at the thrift shop's new location. A printed sign promised: ''Return Engagement Shall Return.''
During the suspenseful intermission, no reassuring meow or protesting caterwaul was heard from behind the brown-paper curtain. Perhaps the cats were there all the time, enjoying discreet privacy. Perhaps they were shared out among the thrift-shop staff. I don't know and it seemed tactless to ask. In the way of felines, the cats of Return Engagement know how to keep their own counsel.
When Return Engagement reopened for business, the cats seemed to take the new premises in stride, so to speak. Perhaps, on the first day, they made those catlike inspection tours to reconnoiter the new ground, consider its possibilities, and otherwise satisfy curiosity. But it was no big deal.
That may have been due partly to the fact that the Return Engagement cats are transients. The little shop on First Avenue is a temporary haven - not a shelter. The feline and occasional canine guests are on the premises only until adoption. (One ''unadoptable'' cat, which knew a good berth on sight, has hung around for eight years, but she is an exception.) The animals, which never number more than about half a dozen, are brought in by the shop's personnel. The temporary boarders are but a handful of the thousands of pets lost or abandoned in our city every year.
All week long, the cats share Return Engagement with the sales people and customers. But on Sunday, the cats take complete possession. Small cats. Large cats. Tigers in gray and orange. Black cats. White cats. Siameses. Tabby cats. But no fat cats.
They dispose themselves among the knickknacks and small objects, the Oriental hangings, the cabinets and chests. They lie magnificently stretched out and decorously draped. As Old Possum observed, ''They like to practice their airs and graces.'' They stretch, or yawn, or wash themselves. Or they sit cat-still, like porcelain figurines, gazing fixedly at the human world beyond the glass, but with never a blink of recognition. Occasionally, they change position or move, usually with great deliberation, to some new vantage point. Once in a while, one of the more energetic leaps to a high plateau, as if sprung from some invisible catapult. But none of this is for the audience. The cats do not perform or posture for our benefit. Remote self-composure is their natural state.
Return Engagement used to display a hand-lettered sign reading: ''Please do not bang on the window. The cats will pay no attention.'' Perfectly true. Like countless others who don't believe in signs, I once ventured a few tentative taps. The cats proved impervious to tappery. I am convinced that, had a cat been portering the gate in Act II of ''Macbeth,'' it would have sat immobile throughout the clamorous knocking or would have walked quietly and perhaps disdainfully away. The Glamis gate would still be shut.
Perhaps in part because of the creatures' very aloofness, most passers-by find the cat sideshow irresistible. People interrupt their strolling, take in the window scene, and exclaim, ''Look at the cats!'' in tones of such surprise and delight you would think they had never seen a cat before. That is when the window banging is likely to start. But it's no use. If the cats react at all, it is to move sedately away from the commotion.
About their movements. It is not true - and truthful cat owners will confirm this - that cats never knock anything over or cause any damage. I've heard of assorted catastrophes - even to the shredding of a set of hard-cover books. But it is also true that cats can move so sure-footedly that even the most delicate ornament remains unjarred by the silent tread of little cat feet. Cats can not only look at kings. They can coexist with Royal Doulton.
Until the day when there are no more animal refugees, I see that the need will continue for shelters and temporary havens, and for groups like the Society for Animal Rights. They reflect a decent concern for defenseless creatures whose rights would otherwise go undefended. That is really what the cats in the window on Beekman Hill are all about.