Spiked Mines

"Rigged with heavy explosives, the spiked balls are set to go off when they lose all their spikes."

- BTD5 Official Description

 is the final upgrade for path 1 of the Spike Factory in Bloons Tower Defense 5. Each spiked ball can pop up to 16 bloons before exploding. It cost $11900 on Easy, $14000 on Medium, $15120 on Hard. There is a skull on top of the spiked mine production chute, and a skull on top of the mines it produces. This upgrade rigs the spike balls with heavy explosives, causing them to go off when they lose all their spikes. The explosion gives bloons a napalm effect, similar to the Mortar Tower's Burny Stuff upgrade. The napalm pops bloons every 2 seconds for 6 seconds. The popping power of the explosions are as strong as 1-0 Sniper Monkeys (pops 4 layers).

Trivia

 * Three of these upgraded 4/0 can easily destroy a MOAB.
 * The explosion's side effect is the same as a 0-2 Mortar Tower, which means the spiked mines contain monkey napalm.
 * This upgrade causes deployment speed of the Spiked Mines to double.
 * The Even Faster Production upgrade will enable the tower to produce spiked balls hypersonically and can destroy a whole bunch of incoming Ceramic Bloons, or any Bloons for that matter, at once.
 * Spiked Mines with Even Faster Production upgrade, Spikes R Us tier 2, and Tack Awesomizer can destroy an entire ZOMG, provided the spike factory is located far enough from the start of the track and the mines are sufficiently concentrated.
 * If Spiked Mines is near a Monkey Village with Jungle Drums upgrade, with Even Faster Production, Spiked Mines will shoot Spiked Balls as fast as a Turbo Charge Boomer with the Ability activated.
 * If the Spiked Mines are not used, they will explode after a while in the same way normal spikes or Spiked Balls disappear after a certain amount of time.
 * If a Spiked Mine Factory is put into the Socket of Power in "The Crucible", it will produce so fast that it appears that the hatch is not moving. This only happens on fast forward, however.
 * Tier 4 Upgrade for Spike Factories is the latest to unlock, the second latest is from Dartling Gun and the third is Mortar Tower, however, it is the third latest in BTD5D, followed by the Monkey Engineer and Bloonchipper, respectively.
 * Spiked mines' explosions are not powerful enough to pop black and zebra bloons. This can be noted by sending a lot of Zebra Bloons at a spiked mines factory in Sandbox Mode.
 * 1 of these (4/2) Can take out a BFB