Collection of sci-fi short stories for younger readers

Question

I've been looking for this for several years, and bugs me that I can't find it...

It was a collection of about 7 - 8 sci-fi short stories geared towards younger readers that I read in the early 80's or so, and I can't remember the name of the book, but do recall some of the details of the stories it contained (not titles though)

• One story was about a lady that lived alone tending her plants and her home got broken into and she was robbed (killed too?) and one of the plants attacked and captured\killed the robbers.

• Another was about a new kid to school that everyone thought was strange and it turned out he was an alien that would go "home" to a UFO. (Discovered when kids followed him one night)

• The story I remember the most was about a police officer of a town in a desert saw huge ships "float" towards the town as he was outside the town in the desert. He heard a loud hum and saw beam of light from the ship hit the town and when he got back in town everyone was gone, and I believe he saw Neanderthal like creatures in their place . The story ended with a future scientist being puzzled uncovering a gun from the site of where the town was in what was assumed to be millions of years later. (I believe the title of this story was something like "the final experiment" or "the last experiment")

The cover of the book had a picture of the Earth in the middle with a target over it like it was in the scope of a gun. I believe some text was on there such as "is anyone up there". It could have been a book from the scholastic book club for elementary\middle schools.

Answer 1

Sounds like The Aliens Are Here! (1980) by D.J. Arneson and Tony Tallarico.

From Goodreads:

"Tonight, when it is dark and nothing makes a sound, look high above you - deep into outer space... "One thing is very clear, you know there are up there! But do you know if they are here? "The husk people and the robot maker...the implanted aliens...the strange kid...the men in black...and the others! "Are they here? "Are they really here?"

From a user review:

This book consists of seven accounts of paranormal experiences, with an emphasis on close encounters with possibly alien beings, targeting a young adult audience, and with little effort to draw the line between fact and fiction. The book is similar in tone and style to the authors' other work, Our Mysterious World, but with the difference that each of the stories goes for several pages, and is written as a narrative. Although some of the stories contain elements from the popular mythology of the paranormal, such as the "Men in Black," none of them are familiar as direct accounts - they appear to be fictional, not based on actual claims. Nevertheless, they should stimulate the imaginations of young minds, and I found them very enjoyable. The illustrations are terribly unprofessional, but in that sense will not intimidate youth of limited artistic talents, who may find it possible to imitate them.