【Catch】 , 【capture】 , 【trap】 , 【snare】 , 【entrap】 , 【ensnare】 ,  【bag】 are comparable when meaning to get into one's possession or under one's control either by taking or seizing or by means of skill, craft, or trickery.

【Catch】 , the ordinary and general term of this group, distinctively implies that the thing laid hold of has been in flight, in concealment, or in constant movement and that possession has been gained by pursuit, force, strategy, or surprise or by means of a device or accident which brings it within one's reach physically, visually, or mentally.

Sometimes the power of laying hold of is ascribed not to a person, his vision or other sense, or his mind, heart, or imagination but to the thing which draws to itself his attention, his eye, or his fancy.

【Capture】  implies heavier odds (as greater opposition or difficulty or more competition) than does 【catch】 and suggests a taking possession that amounts to an overcoming or a victory.

【Trap】 , 【snare】 , 【entrap】 , and 【ensnare】 imply catching by a device which holds the one caught in a position that is fraught with danger or difficulty or from which escape is difficult or impossible.

【Trap】 and 【snare】 imply the use of a 【trap】 or 【snare】 (see LURE n), but 【entrap】 and 【ensnare】  suggest trickery in 【capture】 more often than the use of an actual 【trap】 or 【snare】 : all four terms impute craft to the catcher and unwariness or lack of caution to the one that is caught. Distinctively, 【trap】 and 【entrap】 suggest a being held in a position where one is at the mercy of the captor and his designs, and 【snare】 and 【ensnare】 a being held so that the more one struggles the more desperate becomes one's situation.

【Bag】 carried a double implication of catching (as game or specimens) and of putting into a container (as a game 【bag】 ) for transportation or storage.

So strong is the implication of catching and killing game in this use that the word is often employed without suggestion of putting in a 【bag】 .