Are there any bots that we can use to mirror posts from subreddits?

No one engages in bot content and many completely block it.

There were a lot more during one of the big Reddit migrations but they don’t work.

Communities need engagement and you don’t get that with bot cross posts.

There are whole instances dedicated to mirroring Reddit. However a lot of people on the fediverse oppose such features, on my home instance eg. lemmit is filtered out of /all stream. https://lemmit.online/

Yes, it exists, but that practice is generally frowned upon and discouraged (at least by me)

This already exists, I have seen it used before, don't know any exact repositories though. The reason it's not really used is because it's pointless. What are you trying to achieve with it? Your community won't look more active if it has more posts with zero upvotes and zero comments all made by the same user.

Hiding posts from bots will also hide posts from this bot.

Keep in mind that not everyone here uses Lemmy, so a Lemmy feature isn't a good defense in a federated world like this.

It exists and some Lemmy communities operate that way. It’s not a good idea at all in practice. For example one community mirrors a tech support subreddit. It’s utterly pointless engaging in that community because the person asking the question will never read your answers. You can’t bootstrap a sense of community.

There are rss bots that post stuff on lemmy, like for hackernews. And then as another user mentioned there are some servers like 50501 that mirror reddit and cross post to lemmy.

I think the general problem with such things is.... they post a lot of shit. Sure the top content within a community -might- be interesting but you're also going to get pointless junk that just fills up the fediverse. Not to mention the other issues with lack of interaction. I think the unfortunate reality is that the long term best thing for the community is hand curating content and posting it yourself. I say unfortunate because that's more work than a bot, but you'll be better able to grow a community. Plus some people like me will just block any bot i see because they generally are a waste of my time

It's easy to make one. But why would you want that?

As time goes by and more and more people join the Fediverse, I'm sure some niche comms will start taking off. I don't like bots mirroring content from somewhere else, even as a help. In fact, I will immediately unsubscribe from any comm that starts doing that. And I'm sure many people also would.