- More Russian vehicles are getting anti-drone "hedgehog" armor
- But the metal armor is heavy, so lighter vehicles can't carry very much
- Incomplete protection exposes vehicles to drone attack
If there's a downside to the new hedgehog armor Russian troops are adding to their armored vehicles to block Ukraine's drones, it's that it's heavy.
And that may be why the most recent vehicles to appear with aluminum "quills"—which can trigger incoming first-person-view drones before they explode on the vehicle's hull—had just a few quills. The incomplete protection left the BTR-70M and BTR-82 wheeled infantry fighting vehicles vulnerable to drone attack.
How Ukrainian drones found targets through fog
Sometime in late November, Russian forces—potentially from the 1st or 252nd Motor Rifle Regiment—attacked Ukrainian positions, apparently north of Lyman in eastern Ukraine's Donetsk Oblast. They rode across the drone-patrolled no-man's-land in BTR-82s and BTR-70Ms.
The former are Russia's latest wheeled IFVs. The latter, rarely seen in Ukraine, are older wheeled IFVs with extensive upgrades.
The Russians attacked under the cover of the thick fog that's typical of Ukrainian winters, and which can ground and blind the FPV drones the Ukrainians count on for their first line of defense.
Ukrainian drone operators have ways of fighting through the fog, however: deploying drones with thermal cameras or A.I.-assisted targeting, or using ground robots or radio eavesdropping to locate targets for blind-flying drones.
One way or another, local Ukrainian forces detected the Russian BTR column.
It didn't help the unfortunate Russians that they took a wrong turn. "Russians decided to attack and, fortunately, got lost a little bit," Ukrainian drone operator "Kriegsforscher" quipped.
Drones took out two BTR-70Ms and a BTR-82. Kriegsforscher claimed his unit hit one of the vehicles and killed six Russians.
Why hedgehog armor fails on lighter vehicles
Drone surveillance of the immobilized and burning vehicles revealed the flaws in their protection. The 16-ton, 10-person BTRs had the usual anti-drone "cope cages" atop their hulls and, welded to the cages, they also sported a few hedgehog quills.
But the sides of the vehicles lacked any add-on armor at all. Omitting extra armor from the sides of a BTR can help its infantry passengers get in and out of the vehicle faster.
It can also save weight: a dense layer of metal quills, repurposed from industrial cabling, can weigh as much as three tons.
The latest Russian "hedgehog" tanks are shown here covered with unraveled heavy metal cable attached to a steel mesh.
— Roy🇨🇦 (@GrandpaRoy2) October 31, 2025
This thick and heavy system is not impregnable of course but it does significantly increase the number of Ukrainian FPVs required to destroy the tank. https://t.co/eNMX0PP4qa pic.twitter.com/MYh8DGVxb6
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The weight-protection tradeoff Russians can't solve
A 50-ton tank might not mind the extra weight. A 16-ton BTR almost certainly does mind. Add too much armor, and a vehicle will struggle to move across soft ground or cross water obstacles. There has been a notable uptick in Russian vehicles getting stuck in rivers and streams across eastern Ukraine.
It's hard to envy the Russians' dilemma:
- Add too little anti-drone armor, and the drones might get through.
- Add too much, and a vehicle might stall out.
The Russian armor dilemma in numbers:
- Hedgehog armor weight: up to 3 tons
- BTR-82 base weight: 16 tons
- Tank weight (can carry full armor): 50+ tons
- BTRs destroyed in this engagement: 3
- Russians killed (claimed): 6
Clearly opting for the former risk over the latter, the Russians in Kriegsforscher's zone didn't get stuck—but they did get droned.
Maybe if they hadn't gotten lost, the BTR crews would've succeeded in crossing the no-man's-land under the cover of fog. Maybe they would've dropped off their infantry. Maybe those infantry would've successfully seized new positions.
But they did get lost, possibly losing their way in the same fog that may have temporarily obscured them from the drones that ultimately struck them. And they weren't wearing enough metal quills to save themselves.
Why can't all Russian vehicles use hedgehog armor?
Hedgehog armor can weigh up to three tons. A 50-ton tank handles this easily, but a 16-ton BTR struggles with mobility—getting stuck in soft ground or failing to cross water obstacles. Russian forces must choose between protection and maneuverability, and lighter vehicles like BTRs can only carry partial coverage, leaving gaps that Ukrainian drones exploit.
The latest Russian "hedgehog" tanks are shown here covered with unraveled heavy metal cable attached to a steel mesh.
— Roy🇨🇦 (@GrandpaRoy2) October 31, 2025
This thick and heavy system is not impregnable of course but it does significantly increase the number of Ukrainian FPVs required to destroy the tank. https://t.co/eNMX0PP4qa pic.twitter.com/MYh8DGVxb6
