How to fire an animation every time a character moves, npc or player?

Okay, so I made a game which I'm not gonna really explain about and I made an animation for movement for one of the npcs. It follows the nearest player, and here's part of the code I have right now: (It's an enemy npc)

while wait() do
	local player = FindPlayer()
	if player ~= nil then
		h:MoveTo(player.Character.HumanoidRootPart.Position)
		if not walk.IsPlaying and player.Character.Humanoid.Health >= 1 then
			walk:Play()
		elseif player.Character.Humanoid.Health <= 0 then
			walk:Stop()
			player.Character.HumanoidRootPart:Destroy()
		end
	else
		h:MoveTo(spawnCF.p)
	end
end

Is there any way to detect if the character is moving, and when it does, run the animation?

This is my whole script (it also makes the humanoid move towards the nearest player):

local h = script.Parent.Humanoid
local walkAnimation = script.Walk
local walk = h:LoadAnimation(walkAnimation)

script.Parent.Humanoid.Running:Connect(function()
	walk:Play()
	script.Parent.Humanoid.StateChanged:Connect(function(oldState, newState)
		if (newState == Enum.HumanoidStateType.Seated) then
			walk:Stop()
		end
	end)
end)

local torso = script.Parent.HumanoidRootPart
local spawnCF = torso.CFrame

script.Parent.HumanoidRootPart:SetNetworkOwner(nil)

function FindPlayer()
	for _, v in next, game.Players:GetPlayers() do
		if v.Character then
			local char = v.Character
			if char:FindFirstChild("Humanoid") and char:FindFirstChild("HumanoidRootPart") then
				local ptorso = char.HumanoidRootPart
				if (ptorso.Position - torso.Position).magnitude <= 125 then
					return v
				end
			end
		end
	end
	return nil
end

while wait() do
	local player = FindPlayer()
	if player ~= nil then
		h:MoveTo(player.Character.HumanoidRootPart.Position)
		if player.Character.Humanoid.Health <= 0 then
			player.Character.HumanoidRootPart:Destroy()
		end
	else
		h:MoveTo(spawnCF.p)
	end
end