hi kateyoup personally i would not feed my fish with them as i use them to go fishing but i have used squats which are like a maggot only smaller and i have only gave them to my goldfish and a little tench what i found in my net from a fishing trip. but you look at the size of a maggot and a guppy and start wondering how it will fit into its mouth. but like i said thats my personal opinon hpe its some use