Thanks for reaching out to this question. Here is information on poison hemlock: Poison hemlock identification and control - Agriculture (msu.edu). 

Poison hemlock is in many parts of Michigan. I have not heard reports of honey bee poisoning from foraging on poison hemlock. Honey bees will forage on many plants that are in bloom, so we can expect the overall amount of nectar/pollen from poison hemlock to only be a small portion of the total nectar/pollen in the hive.

Happy beekeeping!