What I do is take the Scripture as it is, and I try not to make assumptions or unwarranted conclusions about what it does not say.
1 Peter 5:8 says "the devil" (singular) prowls around, looking for someone to devour." That says to me that it is discussing one, the devil, who in and of himself only is doing this "prowling". The verse doesn't mention demons, and it doesn't say anything about the activity of demons, whether they do similarly or not.
Once we establish and agree on what the text actually says, then we can discuss what it might mean.
1 Peter 5:8 says "the devil" (singular) prowls around, looking for someone to devour." That says to me that it is discussing one, the devil, who in and of himself only is doing this "prowling". The verse doesn't mention demons, and it doesn't say anything about the activity of demons, whether they do similarly or not.
Once we establish and agree on what the text actually says, then we can discuss what it might mean.