i told her i posted about this and she has an update (which i guess content warning for animal harm [the animal did it to it's damn fool self])
she found this out the first time when she auto-started her truck to warm it up before work one below-freezing morning and came out ~5 minutes later to find (the then unnamed) diesel with her head stuffed in the tail pipe hanging limply by her idiot neck and thought that she was dead, ran over and pulled her out, and the chicken went "oh hi! anyways mind if i get back in there?" and did it a-fucking-gain??
best guess is bc she feeds her chickens with a pvc gravity pipe like this
and despite having ~40 other chickens who don't fuck this up, diesel went "food comes from tubes, this is tube, ∴ this is the ~secret~ food hole that the others do not know about. i will be rewarded with golden seed for being the cleverest of them all :)" and is now on 24/7 vehicle related suicide watch. fine line between docile and dumb sometimes.