user3624: Somebody with the privilege should create the tag synonym olfaction <- olfactory (I don't have the tag count to do so). I could retag all Qs that use "olfactory" but this would bring them all to the top of the activity cue.
Just a small step in a well-needed tag cleanup...

user6: I've merged the two tags, I didn't create a synonym as I don't think this would provide any advantage. olfaction will be the only choice presented to users.

3624: <p>Somebody with the privilege should create the tag synonym <a href="https://biology.stackexchange.com/questions/tagged/olfaction" class="post-tag" title="show questions tagged &#39;olfaction&#39;" rel="tag">olfaction</a> &lt;- <a href="https://biology.stackexchange.com/questions/tagged/olfactory" class="post-tag" title="show questions tagged &#39;olfactory&#39;" rel="tag">olfactory</a> (I don't have the tag count to do so). I could retag all Qs that use "olfactory" but this would bring them all to the top of the activity cue.</p>

<p>Just a small step in a well-needed tag cleanup...</p>
 6: <p>I've merged the two tags, I didn't create a synonym as I don't think this would provide any advantage. <a href="https://biology.stackexchange.com/questions/tagged/olfaction" class="post-tag" title="show questions tagged &#39;olfaction&#39;" rel="tag">olfaction</a> will be the only choice presented to users.</p>
