I get repetition as a technique, I'm just saying I'm not a fan of the amount.

I like the idea of death as a door, but I think you repeated it a bit too much. I also think that the poem would do well with a few more fleshed-out ideas. Maybe references to different kinds of doors (a swinging restaurant door comes to mind, revolving, double doors, I dunno, there are lots of kinds of doors haha), different landscapes beyond the door. 

I felt like the messages contained within this poem were interesting. Death as an insect infested door anyone?'...anyway it seemed way too concise way too at the actual idea, as opposed to if you skirted it a bit then maybe it would convey the images of people being afraid of insects or blood sucking monsters more. Though I also felt that maybe the seriousness of the poem was a bit meditated on: that maybe the writer is writing from personal experience of either their own brief experience or the lasting experience of someone they know.

Took your suggestion. 8/10 would do again.

Regarding your final line of reply - personal insults aren't allowed here.  This is your warning.

The repetition of "death is a door" is really cool, but the way it's done would work more for a song than for this poem, at least as it reads right now. Maybe having separate stanzas rather than one long stanza would make it seem a bit more fitting, if it was the beginning or the end of every stanza. Even not saying it as often would be helpful--maybe three times instead of six. As it is, you get your point across when you only say it once or twice, but the repetition would be there if you said it three times.

Another idea is that you could try to make the metaphor more implicit rather than explicit. As it is, we know that death is a door through some of your imagery, and I'm not sure that you need to say what you're comparing death to. I'm not sure how to word this. But I'll try. 

There are two parts to a metaphor: the vehicle and the tenor. The vehicle is what the tenor is being compared to, so in your case the tenor is death and the vehicle is a door. You could try making the teno

I like the central idea.

One small suggestion - maybe replace "covered by insects" with "crawling with insects." I think the second option just adds a bit more to the imagery you're building. 

Death is a Door