Some members say they will wear masks in more crowded locations, like in airports, on airplanes and in grocery stores. And others flatly refuse to wear them at all.
"Can you smell through that mask?" Rep. Clay Higgins, a Republican of Louisiana, told CNN on Thursday. "Then you're not stopping any sort of a virus. It's part of the dehumanization of the children of God. You're participating in it by wearing a mask."
"What you're wearing is a bacteria trap; it's not helping your health or anybody else's," said Higgins, who had just gotten off a cramped elevator with two other GOP members, none of whom were wearing masks.
Higgins' statement is not supported by the science. Smells do not carry viral particles. Viruses are carried in particles of mucus or saliva that spray from the mouth and nose when people sneeze, cough or talk.
Because members are often in tight corridors in Congress, the Capitol physician, Dr. Brian Monahan, has repeatedly urged members to wear masks, including on the House floor, given the challenges to physically distance.
"Use of a face covering, while voluntary, is strongly recommended for members and staff in any proceeding when it may not be possible to maintain the minimum six-foot separation distance," Monahan, along with House sergeant-at-arms Paul Irving, wrote in a memo to all members of Congress earlier this week.
While most members in both parties wear face coverings throughout the Capitol, including Speaker Nancy Pelosi, a California Democrat, and House Minority Leader Kevin McCarthy, a California Republican, other than when they speak on camera, it's a group of Republicans who choose not to wear face coverings while Democrats universally are spotted wearing masks while in the chamber. Police officers, aides, reporters in the Capitol and all but a couple of senators wear masks -- but a group of House Republicans continue to choose not to, something President Donald Trump has refused to do as well.
The House has taken steps to promote physical distancing by limiting the number of members who can be present at one time on the floor by staggering vote times, while indicating which seats can be occupied to ensure proper spacing. Monahan and Irving said in their memo that "members are encouraged to remain in their offices" unless participating in floor debate. But it is not enforced.
Indeed, a number of GOP members don't heed that advice -- particularly Rep. Louie Gohmert of Texas, who spends much of his time on the floor while interacting with members and not wearing a mask. On Thursday, Gohmert and Rep. Steve King, an Iowa Republican, engaged in a long conversation on the House floor -- while interacting with other members of the House. Neither was wearing a mask, and they were within 6 feet of one another.
"Well, I wear a mask when there's tight quarters and people appreciate that I do," King said Thursday when asked about the matter. "I've been wearing them what I think is in a prudent way."
Others seem to be critical of what the federal government is saying about masks.
Rep. Andy Biggs, an Arizona Republican who's chairman of the conservative House Freedom Caucus, has not been wearing a mask while on the floor with his colleagues and has been carrying on conversations at length with them. He said Thursday he's relying on science from the University of Minnesota about the use of masks -- and noted that public health experts like Dr. Anthony Fauci and US Surgeon General Jerome Adams say wearing a mask isn't always necessary when maintaining a safe social distance.
Asked about Fauci's and Adams' recommendations to wear masks, Biggs said sarcastically: "Yeah, of course, see they've been right on everything, haven't they?"
Biggs added: "Well, the reality is in some places I'll wear a mask. If people feel more comfortable, I will try to accommodate them. In this place? No. ... Plus I'm also getting tested. I've been tested, and I don't have it."
People can catch coronavirus at any time, even immediately after testing negative. And people can spread the virus before they develop any symptoms.
"Well, they're very uncomfortable and I don't believe we need to be wearing them all the time," said GOP Rep. Virginia Foxx of North Carolina, when asked why she hasn't been wearing a mask. She noted that she wears masks when she's on the House floor, though CNN spotted her Thursday on the floor interacting with aides and members without wearing one.
"I wear it for the reason that I believe it is effective," Fauci said on CNN. "It is not 100% effective -- I mean, it's sort of respect for the other person and have that other person respect you. You wear a mask. They wear a mask. You protect each other."
What public health officials are worried about in particular is the spread of the virus among people who are unaware they may have it. And even though the government's top scientists have repeatedly briefed members of Congress, some Republicans seem to have misinterpreted what the science says.
Rep. Chip Roy, a Texas Republican and cancer survivor, has been on the floor for extended periods and hasn't been wearing a mask. He noted Thursday he has been wearing a mask on airplanes and also has done so at recent events around the elderly and near veterans.
Asked why he hasn't been wearing masks on the House floor, Roy said: "Look, the people that we're engaging with -- if I see they're particularly concerned about it, then I step back. But if they're not concerned about it, then I mean, I'll just be honest with you: I'm not either."
Roy added: "Looking at people's faces matters. Constituents being able to see your face matters. I think working and being able to talk to reporters, I think it matters. If I thought for an instant that I was in any ways sick, I think that would also inform my decision. But if I believed myself to be healthy and if I believe that I'm in an open area and if I don't believe I'm around anybody that's particularly vulnerable, then I think I can make a decision that's appropriate for being able to engage with people."
Herd immunity refers to when a large segment of the population is immune to a specific infection, either through widespread transmission or via vaccination, and more people generally have to get vaccinated for that to occur with contagious diseases. There's no vaccine yet for Covid-19.
Higgins, the 58-year-old Louisiana Republican in his second term, said that when he was a police officer he had been to hospitals "hundreds of times" and that doctors and nurses hadn't been wearing masks all day long.
"I have a different medical opinion," he said of wearing masks.
Others seem to wear masks sporadically.
Rep. Paul Gosar, an Arizona Republican, was on the floor Thursday talking with his colleagues and not wearing a mask.
"Sometimes I wear it, and sometimes I don't," Gosar, a dentist for 25 years who said he's used to wearing masks. "I forgot this time."
CNN noted to Gosar that the House provides disposable masks at every entrance for members. Gosar said he hadn't worn one earlier because he "ran in real quick" to vote and returned to the halls to take a phone call.
Yet Gosar then returned back to the House floor without picking up one of the available masks, staying in the chamber for about 11 minutes, including chatting maskless with several colleagues in close proximity -- none of whom were wearing masks.
And in a later vote series Thursday, Gosar had a mask but it was pulled down as he chatted with a maskless Gohmert. He put the mask back on when interacting with Rep. Mike Conaway, a Texas Republican who was also wearing a face covering.
During House votes, many members in both parties cast their votes quickly, leave the chamber and are not present for more than a couple of minutes. But the ones who tend to linger for long periods of time are largely on the GOP side of the aisle.
Rep. Steve Scalise of Louisiana, the House minority whip, has been repeatedly spotted speaking at length on the House floor without a mask while engaging with his GOP colleagues, including this week. When Republican Rep. Greg Walden of Oregon, who was wearing a face covering, approached a maskless Scalise late last month, Walden said to him: "Nice mask."
Scalise responded by pointing to his face: "I wear this for Halloween," prompting laughter from a handful of members surrounding them.
Scalise, the No. 2 Republican, told CNN on Thursday that he wore a mask on the plane from New Orleans, as required, and plans to wear one again when he flies home. Asked why he doesn't wear one in the Capitol, Scalise said he maintains a social distance. "I think that's clearly the most important thing for people for safety."
Scalise said he tries to sit a few seats away from members as they engage in prolonged discussions on the floor. "We miss seeing each other, and even after social distancing it's (important) to be able to talk to your colleagues."
"It's harder to do with a mask," Scalise said of talking with his colleagues. "Also, it's better to talk in person than do it over the phone." He added that sometimes he stays in the chamber rather than return to his office quickly, because he sees "someone on the floor and you have something to talk" about. "That's the best way to work through these issues."
Asked if he has concerns about his colleagues who aren't wearing them, Diaz-Balart said: "Look, they're adults. Everyone is an adult, and they know what they're doing."