Keeping frozen bloodworms in the same freezer used for food can raise sanitary concerns. Bloodworms are commonly used as fish food, and while they are safe for aquatic animals, they are not intended for human consumption. For this reason, it's generally best to store them separately from the food items meant for human consumption.
Cross-contamination is a significant concern when it comes to keeping non-human food items with human food items. While the frozen bloodworms themselves may not pose a direct health risk to humans, there is still a potential for them to harbor bacteria or pathogens that could transfer to the food meant for human consumption.
To ensure proper hygiene and prevent cross-contamination, it's advisable to store frozen bloodworms in a separate freezer or a designated container that is not used for storing food meant for human consumption. This will help maintain the cleanliness and safety of the food you eat while also keeping your sister's fish food organized and contained.