The boundaries between sci-fi and horror have been blurred from the early days of cinema. Movies such as Frankenstein and The Invisible Man used sci-fi concepts to evoke major scares, and inevitably the terror of creatures from other worlds became a major part of scary cinema.

Classic alien invasion movies such as War of the Worlds certainly had their scary moments, but for the most part they were sci-fi adventures more interested in thrilling an audience than terrifying them. But by the time The Thing from Another World and Invasion of the Body Snatchers arrived in the 1950s, the emphasis had shifted. These films were fully intent on inflicting maximum scares on their viewers, using the paranoid terror of shapeshifting and human-mimicking aliens to genre-changing effect.

The most influential scary alien horror movie is, of course, Ridley Scott's Alien. The film might have been set in deep space, but it had more in common with the slasher movies of the era than Star Trek or Star Wars, and it ensured that every subsequent movie featuring an alien stalking human prey would be compared to it.

There are plenty of horror movies about aliens available to stream right now, so we've compiled a list of some of the best. These range from ridiculous gorefests to scary arthouse chillers, and everything in-between. Stream these and more on our favorite services, and once you've read this, check out our guide to the best scary alien invasion movies ever.