True to form, another letter appeared from the national director of People for the Ethical Treatment of Animals, Ingrid E. Newkirk, about Takoma Park and its rats {"In Defense of Rats," Oct. 4}. I have never read such irresponsible, unadulterated, idiotic nonsense.

Takoma Park may be a pioneer town, but pioneering days are long past. We are a country of crowded urban and suburban areas, many with aging buildings, replete with food sources -- restaurants, grocery stores, fast-food chains, etc. -- all of which attract mankind's greatest pests, rats and roaches.

Perhaps Ingrid Newkirk and friends, whose reputed goal is to ''educate'' the public, have never suffered the experience of a serious rat problem and would benefit by learning about life in the real world. Having grown up in a clean but aging downtown D.C. apartment building with grocery stores and restaurants nearby, I have less than pleasant memories of rats. Though there were covered trash bins, regular pickups, clean alleys and no human filth (Newkirk's solution), I remember the sounds of rats gnawing behind the walls during the stillness of night, the sight of lids of tin cans nailed over holes where they attempted to get in, a neighbor who awoke with one sitting on him, the photographs of infants and toddlers covered with rat bites. And there was the distress of the mother of an eight-year-old who, with the natural fearlessness and curiosity of childhood, attempted to catch a baby rat in her back yard, hoping to make a pet of it. When cornered, it bit her.

With World War II rent controls, the owner allowed the building to deteriorate and no longer distributed rat poison. (So much for rent controls.) The rats took over. No one ventured into the basement. Normally nocturnal, they ran through the yard and up and down the fire escape in daylight.

Rats are extremely intelligent, filthy, disease-carrying creatures. If constant, diligent efforts are not made to control them, they proliferate; the most effective means of control are traps and poison. If jurisdictions other than Takoma Park were to accept their present stance, the results would be unbearable.

I suggest that the officials of Takoma Park rethink their current position, and that PETA and friends attempt what appears to be the impossible -- a modicum of rational thought.

MARION L. POLLI Derwood