Yh I agree with Guyb93, I dont think ghosts are real and animals reacts to things before they happen because of their superior senses. Some animals react to things that hasn't even happened, like earthquakes for example, because they feel the change of ionisation of the air
They can be eaten by Plecos, but only if they are chopped up. The Pleco can’t eat anything that big.
I have left clams on the half shell and whole shrimp in tanks and the plecos have had no issues eating it, as mentioned they rasp and don't need the food cut into bits. They will scavenge any dead fish in your tanks-those aren't cut up.
I would stick to a vegetation based diet for your Pleco. (Algae, algae wafers, blanched vegetables, etc.)
Many-most plecos are omnivores and will scavenge protein as well as vegetable based foods. Assuming your pleco only eats veggies/plants/wood (yes some need the cellulose in their diet-hence the Morning Wood from Repashy) can be detrimental to its health. Some plecos are carnivores so depend on meaty foods in their diets.
It is good to feed plecos a varied diet including processed food (like wafers and pellets) as well as fresh foods like squash (green/yellow zucchini, opo squash, butternut, honeynut, acorn, carnival, delicata, kabocha, hubbard, cheese pumpkin aka cinderella pumpkin), broccoli/cauliflower/brussels sprout (for a limited time in the tank, few hours at most-will foul water fast), melons (watermelon, cantaloupe, honeydew), other fruits (my BN love green papaya), my plecos love sweet potatoes; orange or the purple variety.
Try for organic if available. If not I always will wash the squash/melon (not the sweet potato/broccoli/cauliflower/brussels sprout) with some Dawn soap and rinse very well. Use common sense with what you put in the tank. A winter squash like a hubbard can be sliced in a wedge and skewered and stay in the tank for 12-24 hours, same with a sweet potato. Something like a watermelon would also be sliced in a wedge (size dependent on what you are feeding) and be in the tank for a few hours because it can break down quickly. Zucchini and opo squash can be sliced in half and de-seeded and left for up to 12 hours. My tetras, rasboras, gouramis and corys also love to eat melons and some summer squash.
I also will occasionally feed the tanks some clams on the half shell, raw shrimp, earthworms, and mussels. The plecos like the first two more than the other two. Many of my tanks also get blackworms and the plecos will also try and take advantage of that if they can. Being shy and since the worms are fed in the day-they usually miss out. I also have earthworm and bug sticks I feed the bottom feeders-including the plecos. Once I find the Repashy box I will start making them some food as well, but its still in the
yet to be opened moving boxes the movers decided to place wherever they wanted instead of where the box said it should go (i.e. KITCHEN

).