Q.What kinds of animals prefer sunflowers?
For the first time, I planted about a dozen sunflowers from seeds. Six came up, one of them quite large and impressive. In the last few days, three of my sunflower plants appear to have been bitten off, but not eaten. Just an almost clean bite or cut through the stem. None of my other garden plants have been harmed–only my precious sunflowers! Just this afternoon I walked around the house to check the survivors, and no new damage was detected. Just minutes ago, my neighbor came to tell me that another one had been cut down. What do you think?
Squirrels, chipmunks, raccoons, dear all will eat Sunflowers.
Don't rule out slugs. They come in the night and will cut a stem off cleanly, sometimes even looking like a knife has cut the plant.
Here are a couple of links for you.
https://www.gardeningknowhow.com/plant-problems/pests/insects/kill-garden-slugs.htm
https://www.gardeningknowhow.com/plant-problems/pests/animals/get-rid-squirrels.htm