diff --git a/src/larvatagger.js b/src/larvatagger.js
index 093baa33ab862884e10792262fc97665f14f63f5..79eaf6d3dfe1d29f55c823f1a06d6b091c4488fb 100644
--- a/src/larvatagger.js
+++ b/src/larvatagger.js
@@ -34,6 +34,12 @@ const LarvaTagger = (function () {
 		};
 	}
 
+	function focusOnTimeSlider(view) {
+		if (view === undefined)
+			view = document.getElementById("trackviewer");
+		view.querySelector("input[type=range]").focus()
+	}
+
 	function discardLarvaEdits(checkbox, observer, label) {
 		if (checkbox.checked) {
 			checkbox.checked = false;
@@ -74,7 +80,7 @@ const LarvaTagger = (function () {
 		const frag = document.createRange().createContextualFragment(html);
 		const newtr = frag.firstChild.firstChild.firstChild;
 		let tbody = table.getElementsByTagName('tbody')[0];
-		if (tbody == null) {
+		if (tbody === undefined) {
 			tbody = document.createElement('tbody');
 			table.appendChild(tbody);
 		}
@@ -113,7 +119,7 @@ const LarvaTagger = (function () {
 			const option = document.createElement('option');
 			option.value = String(i);
 			option.text = selectOptions[i];
-			if (jlObserver != null) {
+			if (jlObserver !== undefined) {
 				option.ondblclick = () => {
 					JSServe.update_obs(jlObserver, selectOptions[i]);
 				};
@@ -157,6 +163,7 @@ const LarvaTagger = (function () {
 	return {
 		toggle,
 		timeSlider,
+		focusOnTimeSlider,
 		discardLarvaEdits,
 		includeLarva,
 		includeAllLarvae,
diff --git a/src/wgl.jl b/src/wgl.jl
index 6793a06c8861de6c62d473f5c37af655871a7e38..7cd88e604beb0479c75b09294e0a4611847cf99f 100644
--- a/src/wgl.jl
+++ b/src/wgl.jl
@@ -383,6 +383,7 @@ function JSServe.jsrender(session::Session, av::AssayViewer)
     dom = DOM.div(r(session, av.plot),
                   r(session, av.player);
                   class="flex flex-col",
+                  onmouseenter=js"LarvaTagger.focusOnTimeSlider(this)",
                  )
     av.dom = dom
     return r(session, dom)
@@ -905,7 +906,8 @@ function JSServe.jsrender(session::Session, ts::TagSelector)
     end
     JSServe.jsrender(session,
                      DOM.div(elements...;
-                             class="flex flex-col"))
+                             class="flex flex-col",
+                             onmouseenter=js"LarvaTagger.focusOnTimeSlider()"))
 end
 
 function tagselector(controller;
@@ -940,6 +942,8 @@ function JSServe.jsrender(session::Session, tv::TrackViewer)
                   r(session, tv.tagselector);
                   class="flex flex-col",
                   style="display: none;",
+                  id="trackviewer",
+                  onmouseenter=js"LarvaTagger.focusOnTimeSlider(this)",
                  )
     tv.dom = dom
     r(session, dom)