When you like a photo on Instagram, your friends on Facebook will see that you liked it. If you'd like to turn this behaviour off, you can do so with the flick of a switch.
Maybe you don't want others seeing what you've liked on Instagram, or maybe you just don't want to flood their news feeds with all your likes of other people's photos. Whatever the case, just open up Instagram and head to your profile, then click the Options gera > Sharing Settings > Facebook > Share Likes to Timeline. It sounds obvious, but I found it a bit confusing to locate (at least on Android).
We actually discussed this setting when it was first released, but for those that didn't notice — or forgot about it — we thought a reminder was worthwhile.
How Do I Stop My Instagram Likes from Posting to My Timeline? [Facebook Community]