Owing to stealthy acts of hospitality that are largely invisible to government, aid agencies and the news media, hundreds of thousands of people displaced by Hurricane Katrina seem to be disappearing -- into the embrace of their extended families.

It is hard to see and harder to quantify, but kinfolk from Louisiana -- a state that has the most sedentary family structure in the country, with 79 percent of its current residents born here -- are quietly sponging up the bulk of the people whose homes have been destroyed in and around New Orleans, according to Red Cross officials, local politicians and longtime students of Louisiana hurricanes.

"This is certainly the most hospitable place that I have ever worked in," said Teresa Ellis, manager for shelters and feeding for the American Red Cross here in Lafayette, where local officials guess that about 40,000 evacuees have flooded into a city of 110,000. Most of the displaced are now believed to be living with kin.

Ellis, who lives in Indiana and has worked with the Red Cross after four hurricanes in Florida, said the willingness of people in Louisiana to provide housing, food and clothing to large numbers of relatives and family friends is unique in her experience.

A measure of that hospitality can be found at Lafayette's Cajundome, a sports center-turned-shelter. In the past eight days it has received 7,200 people made homeless by the hurricane, but only 1,600 are still there. Relatives arrived to pick up most of the displaced, Ellis said.

"There is no question that family has and will dwarf any other kind of assistance in this disaster," said Carl A. Brasseaux, a professor of history here at the University of Louisiana and director of its Center for Louisiana Studies. "Family ties are still stronger and more viable here than anywhere else in the United States."

Brasseaux, who has written several books on Louisiana's family structure and culture, said that "if family structures in Louisiana had eroded to the point they have in many parts of the country, many refugees here would face a very long and bleak road ahead."

The Federal Emergency Management Agency, the Red Cross and the Salvation Army all said they have no precise numbers on how many people displaced by the hurricane are staying with family or friends or in hotels. The numbers are more precise for those in shelters -- 182,000 people, said Butch Kinerney, a spokesman for FEMA.

But estimates of the total number of evacuees in the Gulf Coast states are dramatically higher than that.

Louisiana officials have said there were more than 1 million evacuees from that state alone, and Mississippi officials have said the total number of people displaced there could be several hundred thousand.

"Without families, we would have a major, major disaster in this part of Louisiana," said Walter Guillory, director of the Lafayette Housing Authority.

Since Katrina struck, the population of Irwin and Mary Thomas's house here in Lafayette has jumped from two to 10. All four bedrooms are full of kin and friends of kin, and a first cousin is sleeping on a folding bed in the parlor.

Sharon Boulet, along with her husband, Steve, and their 10-year-old daughter, Marissa, arrived at the Thomas house on Aug. 30.

Their home in Diamondhead, Miss., on the Gulf Coast was destroyed by a 20-foot storm surge, and the Boulets have nowhere else to live other than here with their Aunt Mary.

All the people living in the Thomas house are middle-class and say they will have no need for government aid because they have insurance or their houses were not severely damaged.

But many people in Louisiana who have taken in kin are likely to be financially squeezed, if, as seems probable, family members stay on for weeks or months.

Clarice Landry has nine evacuees from New Orleans staying with her six-member family in her three-bedroom mobile home on the outskirts of Lafayette. Worried about how all the bills are going to be paid over the coming months, Landry attended a meeting of local relief officials Wednesday to find out if the Red Cross or FEMA would be willing to help.

She was told that, as of now, the Red Cross and the federal government had no money to pay for family caring for family.

"I am doing fine now, but at some point there will come a point where I won't be able to handle it," said Landry.

Her problems are likely to be shared by thousands upon thousands of low-income families in Louisiana who are housing evacuees from the storm, according to the Rev. Herald Alexander, minister of the Church of Christ here.

"I got many members of my church with 25 to 30 people in their homes," he said.

"How they going to pay those bills? On Sunday at church we asked for people to help, but I don't see how we are going to get enough money."

While strains are likely to emerge in the coming weeks, community leaders say that the speed with which families have absorbed displaced people is remarkable, especially compared with the federal response.

"It has been more than seven days, and FEMA is just getting ready to put an office in Lafayette," said Gerald Breaux, director of the Lafayette Convention and Visitors Commission. "If the families and the community didn't step up, we would still be waiting."

Will there be a point, though, when relatives are going to grow weary and resentful of their kin?

Breaux said it will come, of course, but people will be unwilling to say anything out loud.

"When they go to bed at night, will they think about the strain and the cost? Probably," said Breaux. "But why say anything. It is not going to make it any better."

Vedantam reported from Washington.