diff --git a/ARKBreedingStats/Form1.cs b/ARKBreedingStats/Form1.cs
index bf5c7292..dab88684 100644
--- a/ARKBreedingStats/Form1.cs
+++ b/ARKBreedingStats/Form1.cs
@@ -1768,34 +1768,34 @@ private void buttonRecalculateTops_Click(object sender, EventArgs e)
 
         private void aliveToolStripMenuItem_Click(object sender, EventArgs e)
         {
-            SetStatusOfSelected(CreatureStatus.Available);
+            SetStatusOfSelectedCreatures(CreatureStatus.Available);
         }
 
         private void deadToolStripMenuItem_Click(object sender, EventArgs e)
         {
-            SetStatusOfSelected(CreatureStatus.Dead);
+            SetStatusOfSelectedCreatures(CreatureStatus.Dead);
         }
 
         private void unavailableToolStripMenuItem_Click(object sender, EventArgs e)
         {
-            SetStatusOfSelected(CreatureStatus.Unavailable);
+            SetStatusOfSelectedCreatures(CreatureStatus.Unavailable);
         }
 
         private void obeliskToolStripMenuItem1_Click(object sender, EventArgs e)
         {
-            SetStatusOfSelected(CreatureStatus.Obelisk);
+            SetStatusOfSelectedCreatures(CreatureStatus.Obelisk);
         }
 
-        private void SetStatusOfSelected(CreatureStatus s)
+        private void SetStatusOfSelectedCreatures(CreatureStatus s)
         {
             List<Creature> cs = new List<Creature>();
             foreach (int i in listViewLibrary.SelectedIndices)
                 cs.Add(_creaturesDisplayed[i]);
             if (cs.Any())
-                SetStatus(cs, s);
+                SetCreatureStatus(cs, s);
         }
 
-        private void SetStatus(IEnumerable<Creature> cs, CreatureStatus s)
+        private void SetCreatureStatus(IEnumerable<Creature> cs, CreatureStatus s)
         {
             bool changed = false;
             List<string> speciesBlueprints = new List<string>();
@@ -1854,7 +1854,7 @@ private void ShowBestBreedingPartner(Creature c)
                     "Selected Creature not Available",
                     MessageBoxButtons.YesNo, MessageBoxIcon.Question) == DialogResult.Yes)
             {
-                SetStatus(new List<Creature> { c }, CreatureStatus.Available);
+                SetCreatureStatus(new List<Creature> { c }, CreatureStatus.Available);
                 breedingPlan1.BreedingPlanNeedsUpdate = false;
             }
             else
diff --git a/ARKBreedingStats/Form1.library.cs b/ARKBreedingStats/Form1.library.cs
index 186af542..93b35b3c 100644
--- a/ARKBreedingStats/Form1.library.cs
+++ b/ARKBreedingStats/Form1.library.cs
@@ -14,7 +14,6 @@
 using System.Text.RegularExpressions;
 using ARKBreedingStats.library;
 using ARKBreedingStats.settings;
-using System.Runtime.ConstrainedExecution;
 
 namespace ARKBreedingStats
 {
@@ -1712,27 +1711,27 @@ private void toolStripMenuItemRemove_Click(object sender, EventArgs e)
 
         private void toolStripMenuItem2_Click(object sender, EventArgs e)
         {
-            SetStatusOfSelected(CreatureStatus.Available);
+            SetStatusOfSelectedCreatures(CreatureStatus.Available);
         }
 
         private void toolStripMenuItem3_Click(object sender, EventArgs e)
         {
-            SetStatusOfSelected(CreatureStatus.Unavailable);
+            SetStatusOfSelectedCreatures(CreatureStatus.Unavailable);
         }
 
         private void toolStripMenuItem4_Click(object sender, EventArgs e)
         {
-            SetStatusOfSelected(CreatureStatus.Dead);
+            SetStatusOfSelectedCreatures(CreatureStatus.Dead);
         }
 
         private void obeliskToolStripMenuItem_Click(object sender, EventArgs e)
         {
-            SetStatusOfSelected(CreatureStatus.Obelisk);
+            SetStatusOfSelectedCreatures(CreatureStatus.Obelisk);
         }
 
         private void cryopodToolStripMenuItem_Click(object sender, EventArgs e)
         {
-            SetStatusOfSelected(CreatureStatus.Cryopod);
+            SetStatusOfSelectedCreatures(CreatureStatus.Cryopod);
         }
 
         private void currentValuesToolStripMenuItem_Click(object sender, EventArgs e)
diff --git a/ARKBreedingStats/library/Creature.cs b/ARKBreedingStats/library/Creature.cs
index c92af62b..e9e530a8 100644
--- a/ARKBreedingStats/library/Creature.cs
+++ b/ARKBreedingStats/library/Creature.cs
@@ -249,9 +249,24 @@ public CreatureStatus Status
             get => _status;
             set
             {
+                if (_status == value) return;
+
+                if (Maturation < 1)
+                {
+                    if (value == CreatureStatus.Dead)
+                        PauseMaturationTimer();
+                    else if ((_status == CreatureStatus.Cryopod || _status == CreatureStatus.Obelisk)
+                             && (value == CreatureStatus.Available || value == CreatureStatus.Unavailable))
+                        StartMaturationTimer();
+                    else if ((_status == CreatureStatus.Available || _status == CreatureStatus.Unavailable)
+                             && (value == CreatureStatus.Cryopod || value == CreatureStatus.Obelisk))
+                        PauseMaturationTimer();
+                }
+
                 _status = value;
                 // remove other status while keeping the other flags
                 flags = (flags & CreatureFlags.StatusMask) | (CreatureFlags)(1 << (int)value);
+
             }
         }
 
@@ -420,25 +435,32 @@ public void RecalculateNewMutations()
         /// <summary>
         /// Starts the timer for maturation.
         /// </summary>
-        private void StartTimer()
+        private void StartMaturationTimer()
         {
             if (growingPaused)
             {
                 growingPaused = false;
-                growingUntil = DateTime.Now.Add(growingLeft);
+                if (growingLeft.Ticks <= 0)
+                    growingUntil = null;
+                else
+                    growingUntil = DateTime.Now.Add(growingLeft);
             }
         }
 
         /// <summary>
         /// Pauses the timer for maturation.
         /// </summary>
-        private void PauseTimer()
+        private void PauseMaturationTimer()
         {
             if (!growingPaused)
             {
                 growingPaused = true;
-                growingLeft = growingUntil?.Subtract(DateTime.Now) ?? new TimeSpan();
-                if (growingLeft.TotalHours < 0) growingLeft = new TimeSpan();
+                growingLeft = growingUntil?.Subtract(DateTime.Now) ?? TimeSpan.Zero;
+                if (growingLeft.Ticks <= 0)
+                {
+                    growingLeft = TimeSpan.Zero;
+                    growingUntil = null;
+                }
             }
         }
 
@@ -448,8 +470,8 @@ private void PauseTimer()
         public void StartStopMatureTimer(bool start)
         {
             if (start)
-                StartTimer();
-            else PauseTimer();
+                StartMaturationTimer();
+            else PauseMaturationTimer();
         }
 
         /// <summary>
@@ -460,11 +482,8 @@ public void StartStopMatureTimer(bool start)
         public string GrowingLeftString
         {
             get => System.Xml.XmlConvert.ToString(growingLeft);
-            set
-            {
-                growingLeft = string.IsNullOrEmpty(value) ?
+            set => growingLeft = string.IsNullOrEmpty(value) ?
                     TimeSpan.Zero : System.Xml.XmlConvert.ToTimeSpan(value);
-            }
         }
 
         /// <summary>