take the bit between one's teeth

[GoesStation]

Yes, but when a horse takes the bit between his teeth, he gets out of control and runs so fast that his rider cannot stop him.

Isn't the bit, in its normal position between the horse's teeth, the primary tool the rider uses to control the horse?

[gamechanger]

Isn't the bit, in its normal position between the horse's teeth, the primary tool the rider uses to control the horse?

As far as I know, the bit is inserted behind the horse's molars. When the rider pulls the bit, the horse feels pain, which makes him remain under the rider's control. However, some smart horses can somehow remove the bit from the back of their molars and place it between their molars. And then they bite with force, lest the bit slide back to its original position. When this happens, the horse refuses to obey the commands of his rider as no longer does he feel pain.

[Piscean]

Actually, everything was fine until yesterday. We were on intimate terms. Whatever decision we were to make, we always reached a heartfelt consensus. Whatever happened happened last night. He was no longer as intimate as he used to be. He began making any decisions on his own. He didn't even listen to me once. Apparently he took the bit between his teeth (=became disobedient).

The main meaning of the English idiom is, as Skrej said taking control of a situation. When the horse takes control away from the rider, this element of taking control is more important than that of any notion of disobedience. We extend that idea, again as Skrey said,to mean starting or getting on with a task, because we're taking control of the situation and starting, instead of doing nothing, and we're doing so in a decisive or controlling manner.

The idiom is not really appropriate in your original situation:

Actually, everything was fine until yesterday. We were on intimate terms. Whatever decision we were to make, we always reached a heartfelt consensus. Whatever happened happened last night. He was no longer as intimate as he used to be. He began making any decisions on his own. He didn't even listen to me once. Apparently he took the bit between his teeth (=became disobedient).

'Making decisions on his own' when he had previously reached consensus decisions with the writer is not really a dramatic enough change of control. If 'he' had been completely under the control of the writer and then thrown off that control and forged ahead with his own plans, then we might say that he had the bit between his teeth.

[Tdol]

Idioms often take on their own life- many idioms that are related to sailing, for instance, originally meant something very different - sail close to the wind is one example. So, no matter how illogical you find it, you simply have to accept that the idiom is used this way.

[Coloradoguy]

In American English we rarely use this phrase. When used it would be specifically related to approaching a difficult task. Like from the horse's point of view, biting down to focus on the task.

Not a teacher.

[Rover_KE]

Welcome to the forum, Coloradoguy.

Please read this extract from our Posting Guidelines:

You are welcome to answer questions posted in the Ask a Teacher forum as long as your suggestions, help, and advice reflect a good understanding of the English language. If you are not a teacher, you will need to state that clearly in your post.

[probus]

Yes, but when a horse takes the bit between his teeth, he gets out of control and runs so fast that his rider cannot stop him.

That is literally true, but the expression is an idiom. That means it cannot be interpreted according to the usual meaning of its words.

[Tarheel]

To "take the bit between one's teeth" means to face up to a difficult task and do it.

Hm.

[Rover_KE]

kamui23, your post is ungrammatical, you have stated you are not a teacher of English, and your profile is incorrect.