Shalebridge

This location on the map consists of Broken relay tower, Shalebridge Tunnels and Shalebridge Hills. The latter two are rival ant colonies. It is considered to be the most bugged (no pun intended) area in the game.

Shalebridge

 * There usually is a dead Ant Researcher in a pool of water near the eggs in the friendly ant tunnels that has a Big Book of Science on his corpse. Wait 73 hours for the book and the dead researcher to respawn.
 * Quite a bit to the east of Shalebridge Tunnel entrance (Due south of the train wreckage, across the irradiated mudhole) there is an ant egg clutch (it is on the other side of the rocky hill) with a copy of D.C. Journal of Internal Medicine and a Stealthboy underneath the dead Raider. (See Abandoned Car Fort.)

Shalebridge Tunnels
Important Notes: See Bugs sections!

Shalebridge Tunnels is a small cave system that is home to a small, friendly mutated ant colony. The entrance is to the north from the broken relay station located just below the hill and resembles a circular plate or cover surrounded by glowing mushrooms.

When the player enters, the smaller friendly ants are under attack from larger, more aggressive ants. The larger ants will attack the player and can be killed to protect the colony. The larger ants will not be here if you have already killed the queen in Shalebridge Hill.

If you inspect a nearby ant egg cluster, the option to inject a stimpak is given. There is an Ant Compost Heap with some Ant Nectar in it and it will replenish faster upon killing Ant Queen in Shalebridge Hill. The compost pile is toward the back of the cave, to the right, with glowing green mushrooms around it.

If you kill and then search one of the larger ants you will get this message:


 * It appears that these ants are from another ant colony. Perhaps attacking this rival colony would help the forager ants survive.

Hidden Tunnels
On the local map there are what appear to be openings to tunnels that are not found when you go to that point on the map, two of these make a complete small loop, and another appears to be a long tunnel along the outside of the cave to the left.

Climbing up on the boulders to the left of the first two pillars in the first large room near a small puddle, you will find you can continue to walk up the boulders, staying close to the wall. You should be able to get in on the far left side of the opening. You may need to crouch to get in, but once in you can stand up - even Fawkes can get in here. There appears to be another opening on the left, but you cannot get through this one. Straight ahead or to the right is one of these small loops, it is however a closed loop and does not lead to the long tunnel on the left. The opening to the left of this hidden entrance can be accessed partly from the opposite side - similarly by bouldering up. This is directly ahead of the entrance to the Shalebridge tunnels at the south end of the small loop. There is another small opening that appears to be the entrance to the long tunnel below it, on the ground level. You cannot enter either opening, even when crouched. A similar inaccessible opening is at the very end, centered in the back wall of the last cave with the eggs and the compost pile.

Shalebridge Tunnels specific bugs

 * Do NOT loot any of the invader ants, as it will trigger a message that makes the game freeze upon reentry of the tunnels. This includes loading a save made within the tunnels, and it is thus possible to make a playthrough impossible to continue, should all saves be made within the tunnels after receiving the message, unless there are backup saves.
 * It is possible for your game to freeze upon re-entry of the friendly ant colony without looting any of the invader ant cadavers.

Shalebridge Hill
This colony is just north of Shalebridge Tunnels. There is not much here except Ant Workers, Ant Soldiers and an Ant Queen.
 * An interesting way to get rid of her is to try remain as high as possible and cripple her antennae, causing her to frenzy. She will start attacking her former fellow ants who have numbers on their side, so she will get swarmed and die. A flamer will also work quite well.
 * There are also Mentats, Metal Armor and Jet in a pile of bones, through the tunnel on the right as you enter the Invaders/Queens Lair. (You have to jump over the rock to get through the tunnel)

Shalebridge Hill specific bugs

 * The Queen Lair has only minor loot, 10mm Pistol, 10mm ammo, shotgun shells and 5.56mm ammo. The 5.56mm ammo is bugged however so don't try to pick it up or you will experience critical error. (No visible error seen when picking it up in the PS3 version or 360 version, however, it seems to crash the application consistently for some PC users.) (with the 1.1 patch this seems to be fixed, this would CTD my game every time. Now it does not) A Scoped .44 Magnum with ammo can be found near a rotting Brahmin corpse.
 * Followers that follow you into the Hill tend to get stuck at the entrance due to spawning in the ground. Clover, especially has issues with this and seems to die after a few minutes if left there. Also, Star Paladin Cross does this sometimes when entering the Hill. Just walk away from the entrance, and your companion will spawn back up onto ground. (If not killed from being underground too long.)

Other Bugs

 * In the PS3 version, NPC Star Paladin Cross won't follow you into either the tunnel or the hill. However, she will suddenly appear inside after you travel in a ways and have no problems following you after that. Fawkes also displays this behavior, which puts forth the possibility that any of the humanoid NPCs will behave in this manner as well (Charon should follow you just fine).
 * After injecting the stimpaks into the hive and then killing the Ant Queen, there is a chance you cannot enter the tunnel anymore. This issue has been spotted on Xbox360 versions. The game will freeze on loading screen when you attempt to enter the tunnels after the enemy queen is dead.
 * The trigger for this bug appears to be "inspecting" (attempting to loot) the invader ants' corpses ("It appears this ant is from..." message). Upon exiting the tunnels, it will always freeze upon returning. Best course of action is to NOT interact with the corpses when killed. Though sometimes the game may freeze even if you don't.
 * The game can also freeze by looting the two Yao Guai's in the area.
 * The Ant Researcher seems to be falling through the ground an awful lot if you kill him near the pool, lead him away or decapitate him (PS3 confirmed). This is, of course, if you find him actually alive.
 * On the 360 version if you attempt to access the 'Ant Compost Heap' in the forager ant tunnel and receive the message "With the rival queen ant dead, these forager ants should be able to make necter faster", it will trigger the freezing bug. Now if you exit the tunnel and try to re-enter, the game will freeze 100% of the time at the loading screen on re-entry. (confirmed)
 * After extensive testing: Ants appear to be the cause of at least one type of crash. To solve this, changing mode to Very Easy and Sneak Attacking with an energy weapon to turn them into dust. Ant bodies appear to cause framerate issues. (User tried a shotgun to kill all of them which caused the XBox 360 framerate to drop below 10fps.)

Bug fix
This is a step-by-step guide how to prevent the freezing if you're on an XBOX 360.

Please remove this if you follow this exactly, and still have problems.
 * 1. Save your game just before you enter the tunnel for the first time.
 *  2. Go inside the tunnel.
 * 3. Kill all the ants and the Ant Researcher.
 * 4. Loot the book, and touch nothing else.
 * 4. Leave the tunnel.
 * 5. Wait outside for 24 + 24 + 24 + 5 hours.
 * 6. Repeat from one, notice the saving is an advice and after you killed the ants for the first time; they won't respawn.

(It has been suggested that you leave the cell entirely for step 5, ie go to Megaton, Rivet City, Tenpenny Tower, or anywhere safe and away from the Shalebridge cell. The idea is to have the ENTIRE Shalebridge area, both interior and exterior respawn before re-entering the tunnels.  If there are no enemies in the exterior when you return, then DO NOT go back into the tunnels, as you will probably freeze up)

Trivia

 * An easter egg of sorts exists in the "friendly" ant caves, only accessible in the PC version using the tcl console command. Using the *tcl* console command, the player will find a extremely large Radiation King radio directly underneath the egg pile in which a stimpack is used. It does nothing, and approaching it merely says "Activate egg pile". The radio was likely placed there for technical reasons.