Bats don't mind bonking their heads. In fact they love it!

src/main/java/com/minelittlepony/unicopia/ability/BatPonyHangAbility.java

@@ -39,7 +39,7 @@ public class BatPonyHangAbility implements Ability<Multi> {
             return new Multi(BlockPos.ZERO, 0);
         }
 
-        BlockPos poss = RayTraceHelper.doTrace(player.getOwner(), 5, 1, EntityPredicates.EXCEPT_SPECTATOR).getBlockPos().orElse(null);
+        BlockPos poss = RayTraceHelper.doTrace(player.getOwner(), 3, 1, EntityPredicates.EXCEPT_SPECTATOR).getBlockPos().orElse(null);
         if (poss != null) {
             boolean air = player.getWorld().isAir(poss.down()) && player.getWorld().isAir(poss.down(2));
 
@@ -72,7 +72,10 @@ public class BatPonyHangAbility implements Ability<Multi> {
         if (data.hitType == 1 && player.canHangAt(data.pos())) {
             player.getOwner().teleport(data.x + 0.5, data.y - 2, data.z + 0.5);
             player.getOwner().setVelocity(Vec3d.ZERO);
-            attr.addPersistentModifier(PlayerAttributes.BAT_HANGING);
+
+            if (!attr.hasModifier(PlayerAttributes.BAT_HANGING)) {
+                attr.addPersistentModifier(PlayerAttributes.BAT_HANGING);
+            }
         }
     }
 

src/main/java/com/minelittlepony/unicopia/entity/player/PlayerPhysics.java

@@ -13,6 +13,7 @@ import net.minecraft.block.Block;
 import net.minecraft.block.BlockState;
 import net.minecraft.entity.Entity;
 import net.minecraft.entity.EntityPose;
+import net.minecraft.entity.attribute.EntityAttributeInstance;
 import net.minecraft.entity.damage.DamageSource;
 import net.minecraft.entity.player.PlayerEntity;
 import net.minecraft.nbt.CompoundTag;
@@ -83,7 +84,10 @@ public class PlayerPhysics extends EntityPhysics<Pony> implements Tickable, Moti
         if (!creative) {
             entity.abilities.flying |= (canFly || entity.abilities.allowFlying) && isFlyingEither;
 
-            if ((entity.isOnGround() && entity.isSneaking()) || entity.isTouchingWater() || entity.horizontalCollision  || entity.verticalCollision) {
+            if ((entity.isOnGround() && entity.isSneaking())
+                    || entity.isTouchingWater()
+                    || entity.horizontalCollision
+                    || (entity.verticalCollision && (pony.getSpecies() != Race.BAT || velocity.y < 0))) {
 
                 if (entity.abilities.flying && entity.horizontalCollision) {
                     handleWallCollission(entity, velocity);
@@ -108,6 +112,17 @@ public class PlayerPhysics extends EntityPhysics<Pony> implements Tickable, Moti
 
         if (canFly) {
             if (isFlying()) {
+
+                if (pony.getSpecies() == Race.BAT && entity.verticalCollision && pony.canHangAt(pony.getOrigin().up(2))) {
+                    EntityAttributeInstance attr = entity.getAttributeInstance(PlayerAttributes.ENTITY_GRAVTY_MODIFIER);
+
+                    if (!attr.hasModifier(PlayerAttributes.BAT_HANGING)) {
+                        attr.addPersistentModifier(PlayerAttributes.BAT_HANGING);
+                        entity.setVelocity(Vec3d.ZERO);
+                        return;
+                    }
+                }
+
                 int level = pony.getLevel().get() + 1;
 
                 if (ticksInAir++ > (level * 100)) {

src/main/java/com/minelittlepony/unicopia/entity/player/Pony.java

@@ -34,6 +34,7 @@ import com.mojang.authlib.GameProfile;
 import net.minecraft.block.BlockState;
 import net.minecraft.entity.Entity;
 import net.minecraft.entity.attribute.DefaultAttributeContainer;
+import net.minecraft.entity.damage.DamageSource;
 import net.minecraft.entity.data.DataTracker;
 import net.minecraft.entity.data.TrackedData;
 import net.minecraft.entity.data.TrackedDataHandlerRegistry;
@@ -81,6 +82,8 @@ public class Pony implements Caster<PlayerEntity>, Equine<PlayerEntity>, Transmi
     private boolean prevSneaking;
     private boolean prevLanded;
 
+    private int ticksHanging;
+
     @Nullable
     private Race clientPreferredRace;
 
@@ -255,21 +258,25 @@ public class Pony implements Caster<PlayerEntity>, Equine<PlayerEntity>, Transmi
 
     private BlockPos getHangingPos() {
         BlockPos pos = getOrigin();
-        return new BlockPos(pos.getX(), getOwner().getEyeY() + 1, pos.getZ());
+        return new BlockPos(pos.getX(), pos.getY() + entity.getEyeHeight(entity.getPose()) + 2, pos.getZ());
     }
 
     @Override
     public void tick() {
 
         if (isHanging()) {
-            gravity.isFlyingSurvival = false;
+            if (ticksHanging++ > 40) {
-            gravity.isFlyingEither = false;
+                if (Entity.squaredHorizontalLength(entity.getVelocity()) > 0.01
-            entity.abilities.flying = false;
+                        || entity.isSneaking()
+                        || !canHangAt(getHangingPos())) {
 
-            if (Entity.squaredHorizontalLength(entity.getVelocity()) > 0.01 || entity.isSneaking() || !canHangAt(getHangingPos())) {
+
-                entity.getAttributes().getCustomInstance(PlayerAttributes.ENTITY_GRAVTY_MODIFIER).removeModifier(PlayerAttributes.BAT_HANGING);
+                    entity.getAttributes().getCustomInstance(PlayerAttributes.ENTITY_GRAVTY_MODIFIER).removeModifier(PlayerAttributes.BAT_HANGING);
-                entity.calculateDimensions();
+                    entity.calculateDimensions();
+                }
             }
+        } else {
+            ticksHanging = 0;
         }
 
         gravity.tick();
@@ -303,6 +310,11 @@ public class Pony implements Caster<PlayerEntity>, Equine<PlayerEntity>, Transmi
 
         prevSneaking = entity.isSneaking();
         prevLanded = entity.isOnGround();
+
+
+        if (gravity.isGravityNegative() && entity.getY() > entity.world.getHeight() + 64) {
+           entity.damage(DamageSource.OUT_OF_WORLD, 4.0F);
+        }
     }
 
     public Optional<Float> onImpact(float distance, float damageMultiplier) {