Why won't a trail spawn between the head and the HumanoidRootPart?

Why won't a trail spawn between the head and the HumanoidRootPart? This is a local script in StarterPlayerScripts

local Players = game:GetService("Players")
local mouse = Players.LocalPlayer:GetMouse()
local trail = game.ServerStorage:WaitForChild("Trail"):Clone()
trail.Parent = Players.LocalPlayer.Character.HumanoidRootPart
local attachment0 = Instance.new("Attachment", Players.LocalPlayer.Character.HumanoidRootPart)
attachment0.Name = "TrailAttachment0"
local attachment1 = Instance.new("Attachment", mouse.Hit.p)
attachment1.Name = "TrailAttachment1"
trail.Attachment0 = attachment0
trail.Attachment1 = attachment1