Kyochuu Rettou

The same setting where it involves an island where creatures of a different species exist and would prey on anything they can get their jaws on, even humans, the difference of course, was the kind of characters involve where in Kyochuu Rettou in involves a group of people who have to survive if they're gonna get off the island, while in Gunjou no Magmell, it involves a certain individual whose job was to save any individual who was too foolish to go to the island in search of riches but failed.  

both wake up in an island surrounded by insects with no other choice but to fight and survive 

Both Anime have a interesting horror concept one you have killer insects and the other you have killer aquatic animals that can breath out of the water but both have kinda weird thing also involved I don’t want to spoil it so if you enjoy horror and creatures like the movie bats, rats, birds, etc then these two anime are for you