I remember viewing this film as a child in the mid-90s on basic cable in the United States—TBS or TNT, I think. That means it was probably made in the mid-late 80s or early 90s. possibly earlier, though i doubt it. I don’t think it was a big budget affair however there were a fair amount of special effects.
Don’t recall any actors specifically, though I remember there were child-actors in it.
Plot involved aliens landing and taking over a suburban neighborhood. The part I remember is the aliens setting up shop underground or in caves near the neighborhood, (or adjacent a house’s backyard?) and eventually reproducing enough where they take over. I believe there was a plot line where a child/son character knows about the aliens in the ground/caves, however people don’t believe him. I believe the film culminates with armed forces setting up shop in town to defeat the aliens.
the part I’m unsure about is whether the aliens were taking human form or not, body snatchers rip-off style.