This is one of my father's favourite books, he read a library version in the 80s or 90s in the Netherlands and has found it online, so he knows what he remembers is correct/exists. So it's not from after 2000, but could be older dan 80s. I would like to give this book to him as a surprise, so I'm trying to piece together the title/author without having to ask him.
What I remember is that it's about a space traveler who reaches a planet where he finds people that seem human, but he hardly hears/sees them communicate. I believe he was ill at ease and tried to stay out of their way, but is captured in the end. I think the clue was that they actually were humans who colonized the planet after he left Earth. Because his ship was very slow, it took him much longer to get there than the humans who left after him and had much faster ships.
I believe the title of the book was one word and a very normal word (like bug, insect, spider or something else) and the writer's name was pretty normal as well, probably very American.