Not sure if this is a silly question to ask, but I've noticed that when I use browser Instagram on Firefox it displays emoticons as emojis. For example if I type "<3" (less than 3) it'll display a heart emoji. It doesn't actually convert it In the message though, my friends say it sends what I type.

I'm just wondering why this is happening and how to stop it, I've checked settings for everything and cannot find anything about it. Thank you in advance.