Samneric ratted Ralph out because Ralph was torturing them.
sam and eric
Sam and Eric tells Roger and Jack the location of Ralph`s hiding place, because they were being abused
jack starts the fire to get ralph out of his hiding
setting the forest on fire
In "Lord of the Flies," Ralph's secret hiding place is revealed to Jack and his tribe by Samneric, Ralph's two loyal friends who are captured and tortured by Jack's tribe. Under pressure and fear, Samneric betray Ralph's hiding place to Jack in order to avoid further harm.
Yes, Sam and Eric did reveal Ralph's hiding place to Jack's tribe out of fear and pressure from the other boys. This act ultimately led to Ralph's capture and near-death experience in "Lord of the Flies" by William Golding.
Once Jack is certain that Ralph is hiding in the thicket he puts two different plans into effect. Firstly a boulder is levered from the top of castle rock and sent crashing into the thicket. When this fails to kill Ralph or drive him out of hiding Jack puts his second plan into effect. He lights a fire, hoping to smoke Ralph out of hiding, and unintentionally sets the entire island on fire.
a ship
Ralph doesn't tell Jack about the glasses as Jack already knows about them, mainly because he stole them. Ralph pointed out that Jack could have had fire at any time if he'd simply asked for it but instead he'd come sneaking up like a thief and stole Piggy's glasses. Jack demanded that he repeat the accusation and when Ralph obliged Jack rushed forward and stabbed his spear at Ralph's chest. Ralph managed to block the thrust with his own spear and then swung it around to land a stinging blow to Jack's ear.
Jack's and his tribe first try to drive Ralph from his hiding place in the thicket by sending a boulder crashing into it. When this tactic fails Jack then tries to smoke Ralph out of his hiding place by lighting a fire. Ralph makes his way out of the opposite side of the thicket by surprising and stabbing a 'savage' who is on guard. Ralph runs for it and the savages spread out across the island signalling to each other. Ralph tries hiding again, this time in Simon's secret place but is spotted by another savage, who he attacks and stabs with his spear. The fire which Jack lit soon spread out of control and set fire to most of the island. Ralph ended up stumbling onto the beach, with Jack's tribe in hot pursuit.
Jack and Roger plan to hunt down Ralph the next day and set fire to the island in order to smoke him out of hiding. They want to eliminate Ralph as a threat to their leadership and control over the boys on the island.
If you mean 'what are the strategies formulated by Ralph's oppostion to get Ralph out of the thicket' then there were two strategies. Jack first had a boulder from the top of castle rock sent crashing into the thicket with the intention of either killing Ralph or driving him out of hiding. When this failed Jack then lit a fire, hoping to smoke Ralph out of the thicket.